Time Calculator Money

Time Value of Money Calculator: Calculate Future and Present Value :root { –primary-color: #004a99; –success-color: #28a745; –background-color: #f8f9fa; –text-color: #333; –border-color: #ddd; –card-background: #fff; –shadow: 0 2px 5px rgba(0,0,0,0.1); } body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: var(–background-color); color: var(–text-color); line-height: 1.6; margin: 0; padding: 0; } .container { max-width: 960px; margin: 20px auto; padding: 20px; background-color: var(–card-background); border-radius: 8px; box-shadow: var(–shadow); } header { text-align: center; margin-bottom: 30px; padding-bottom: 20px; border-bottom: 1px solid var(–border-color); } header h1 { color: var(–primary-color); margin-bottom: 10px; } .summary { font-size: 1.1em; color: #555; margin-bottom: 30px; } .loan-calc-container { background-color: var(–card-background); padding: 25px; border-radius: 8px; box-shadow: var(–shadow); margin-bottom: 30px; } .input-group { margin-bottom: 20px; position: relative; } .input-group label { display: block; margin-bottom: 8px; font-weight: bold; color: var(–primary-color); } .input-group input[type="number"], .input-group select { width: calc(100% – 22px); padding: 10px; border: 1px solid var(–border-color); border-radius: 4px; font-size: 1em; box-sizing: border-box; } .input-group input[type="number"]:focus, .input-group select:focus { outline: none; border-color: var(–primary-color); box-shadow: 0 0 0 2px rgba(0, 74, 153, 0.2); } .input-group .helper-text { font-size: 0.85em; color: #6c757d; margin-top: 5px; display: block; } .error-message { color: #dc3545; font-size: 0.85em; margin-top: 5px; display: none; /* Hidden by default */ } .error-message.visible { display: block; } .button-group { display: flex; justify-content: space-between; margin-top: 25px; gap: 10px; } .button-group button { padding: 10px 15px; border: none; border-radius: 4px; cursor: pointer; font-size: 1em; transition: background-color 0.3s ease; flex: 1; } .btn-calculate { background-color: var(–primary-color); color: white; } .btn-calculate:hover { background-color: #003366; } .btn-reset { background-color: #6c757d; color: white; } .btn-reset:hover { background-color: #5a6268; } .btn-copy { background-color: #ffc107; color: #212529; } .btn-copy:hover { background-color: #e0a800; } #results-container { margin-top: 30px; padding: 25px; background-color: var(–card-background); border-radius: 8px; box-shadow: var(–shadow); } #results-container h2 { color: var(–primary-color); margin-bottom: 20px; text-align: center; } .result-item { margin-bottom: 15px; padding: 15px; border: 1px solid var(–border-color); border-radius: 4px; background-color: #fdfdfd; } .result-item label { font-weight: bold; color: var(–primary-color); margin-bottom: 5px; display: block; } .result-item .value { font-size: 1.5em; font-weight: bold; color: var(–primary-color); } .result-item .unit { font-size: 0.9em; color: #6c757d; margin-left: 5px; } .primary-result { background-color: var(–success-color); color: white; padding: 20px; text-align: center; border-radius: 4px; margin-bottom: 20px; } .primary-result .value { font-size: 2.5em; font-weight: bold; } .formula-explanation { font-size: 0.9em; color: #555; margin-top: 15px; padding: 10px; background-color: #e9ecef; border-radius: 4px; } table { width: 100%; border-collapse: collapse; margin-top: 20px; margin-bottom: 30px; } th, td { padding: 12px; text-align: left; border: 1px solid var(–border-color); } thead { background-color: var(–primary-color); color: white; } tbody tr:nth-child(even) { background-color: #f2f2f2; } caption { font-size: 1.1em; font-weight: bold; color: var(–primary-color); margin-bottom: 10px; caption-side: top; text-align: left; } #chartContainer { text-align: center; margin-top: 30px; padding: 25px; background-color: var(–card-background); border-radius: 8px; box-shadow: var(–shadow); } #chartContainer h2 { color: var(–primary-color); margin-bottom: 20px; } canvas { max-width: 100%; height: auto; } .section { margin-top: 40px; padding-top: 30px; border-top: 1px solid var(–border-color); } h2, h3 { color: var(–primary-color); margin-bottom: 15px; } h2 { font-size: 1.8em; } h3 { font-size: 1.4em; } p { margin-bottom: 15px; } ul { list-style-type: disc; margin-left: 20px; margin-bottom: 15px; } li { margin-bottom: 8px; } a { color: var(–primary-color); text-decoration: none; } a:hover { text-decoration: underline; } .faq-list { list-style: none; padding: 0; } .faq-list li { margin-bottom: 20px; padding: 15px; background-color: #f8f9fa; border-left: 4px solid var(–primary-color); border-radius: 4px; } .faq-list li strong { display: block; color: var(–primary-color); margin-bottom: 8px; font-size: 1.1em; } .related-tools { list-style: none; padding: 0; } .related-tools li { margin-bottom: 15px; padding: 10px; border: 1px solid var(–border-color); border-radius: 4px; background-color: #fdfdfd; } .related-tools li strong { display: block; color: var(–primary-color); margin-bottom: 5px; } .related-tools li a { font-weight: bold; } .variable-table { margin-top: 20px; margin-bottom: 30px; } .variable-table th, .variable-table td { padding: 10px; text-align: left; border: 1px solid var(–border-color); } .variable-table th { background-color: var(–primary-color); color: white; } .variable-table td:nth-child(2), .variable-table td:nth-child(3), .variable-table td:nth-child(4) { text-align: center; } .variable-table tr:nth-child(even) { background-color: #f2f2f2; }

Time Value of Money Calculator

Understand how the value of money changes over time due to its earning potential. Calculate future and present values with ease.

Time Value of Money Calculator

Calculate the future value (FV) of an investment or the present value (PV) of a future sum.

Future Value (FV) Present Value (PV) Choose whether to calculate the future value of a present sum or the present value of a future sum.
The current worth of a future sum of money or asset.
The value of an asset or cash at a specified date in the future.
The rate of return expected on an investment, expressed as a percentage.
The total number of compounding periods (e.g., years).
Annually Semi-Annually Quarterly Monthly Daily How often interest is calculated and added to the principal.

Calculation Results

Future Value (FV)
Formula Used:

For Future Value (FV): FV = PV * (1 + (r/n))^(nt)
For Present Value (PV): PV = FV / (1 + (r/n))^(nt)
Where: PV = Present Value, FV = Future Value, r = Annual Interest Rate, n = Number of Compounding Periods per Year, t = Number of Years (Periods).

Growth Over Time

Chart showing the growth of the investment over the specified periods.

Period-by-Period Breakdown

Investment Growth Table
Period Starting Balance Interest Earned Ending Balance

What is the Time Value of Money?

The Time Value of Money (TVM) is a fundamental financial concept that states that a sum of money is worth more now than the same sum will be at a future date due to its potential earning capacity. This principle is based on the idea that money available at the present time is worth more than the identical sum in the future due to its potential to grow in value over time through investment. Essentially, a dollar today is worth more than a dollar tomorrow. This concept is crucial for making informed financial decisions, whether it's investing, saving, borrowing, or evaluating business projects. Understanding the time value of money helps individuals and businesses make strategic choices that maximize wealth and minimize risk. It forms the bedrock of financial planning and investment analysis, influencing everything from retirement savings to corporate capital budgeting. The core idea is that money has a "time value" because it can be invested and earn a return, leading to a larger sum in the future.

Who Should Use a Time Value of Money Calculator?

Anyone involved in financial planning, investing, or making long-term financial decisions can benefit from using a Time Value of Money calculator. This includes:

  • Individual Investors: To estimate the future value of their savings and investments, plan for retirement, or understand the true cost of a loan.
  • Financial Planners: To model different investment scenarios for clients and provide accurate projections.
  • Business Owners: To evaluate the profitability of projects, make capital budgeting decisions, and understand the impact of financing options.
  • Students: To grasp core financial concepts and apply them to practical problems.
  • Borrowers: To understand the total cost of loans over time, considering interest and compounding.

Common Misconceptions about Time Value of Money

Several misconceptions can hinder a clear understanding of TVM:

  • "Interest rates are fixed forever": While some loans have fixed rates, investment returns fluctuate. The calculator uses an assumed rate, but real-world returns vary.
  • "Inflation doesn't matter": TVM calculations often don't explicitly account for inflation. The purchasing power of future money can be eroded by rising prices, meaning the calculated future value might buy less than expected.
  • "Compounding is only for large sums": Even small amounts can grow significantly over long periods due to the power of compounding.
  • "Present value and future value are the same": They represent different points in time and are related by the interest rate and time period. A dollar today is worth more than a dollar in the future.

Time Value of Money Formula and Mathematical Explanation

The Time Value of Money (TVM) is calculated using specific formulas that relate the present value (PV) of a sum of money to its future value (FV), considering the interest rate (r), the number of compounding periods (n), and the time duration (t). The core principle is that money grows over time due to interest or returns.

Future Value (FV) Formula

The Future Value (FV) formula calculates what a current asset or cash amount will be worth at a specified future date, assuming a certain rate of return and compounding frequency. The formula is:

FV = PV * (1 + (r/n))^(n*t)

Present Value (PV) Formula

The Present Value (PV) formula calculates the current worth of a future sum of money or stream of cash flows, given a specified rate of return. It's essentially the reverse of the FV calculation. The formula is:

PV = FV / (1 + (r/n))^(n*t)

Effective Annual Rate (EAR)

The Effective Annual Rate (EAR) adjusts the nominal annual interest rate to reflect the impact of compounding within a year. It provides a more accurate comparison of different interest rates. The formula is:

EAR = (1 + (r/n))^n - 1

Variable Explanations

Understanding the variables used in these formulas is key:

Variable Meaning Unit Typical Range
PV Present Value Currency (e.g., USD) ≥ 0
FV Future Value Currency (e.g., USD) ≥ 0
r Annual Nominal Interest Rate Decimal (e.g., 0.05 for 5%) 0 to 1 (or 0% to 100%)
n Number of Compounding Periods per Year Integer 1 (Annually), 2 (Semi-Annually), 4 (Quarterly), 12 (Monthly), 365 (Daily)
t Number of Years Decimal or Integer ≥ 0
nt Total Number of Compounding Periods Integer ≥ 0

Practical Examples (Real-World Use Cases)

The Time Value of Money concept and its calculator have numerous practical applications in everyday finance and business.

Example 1: Saving for a Down Payment

Sarah wants to save $50,000 for a house down payment in 5 years. She plans to invest a lump sum today and let it grow. If she can achieve an average annual return of 7% compounded monthly, how much does she need to invest today?

  • Calculation Type: Present Value (PV)
  • Future Value (FV): $50,000
  • Annual Interest Rate (r): 7% (0.07)
  • Number of Periods (t): 5 years
  • Compounding Frequency (n): 12 (Monthly)

Using the PV formula: PV = $50,000 / (1 + (0.07/12))^(12*5)

Result: Sarah needs to invest approximately $35,170.73 today.

Interpretation: This calculation shows Sarah the minimum amount she must invest now to reach her goal, highlighting the power of compound interest over time. It helps her set a realistic savings target.

Example 2: Estimating Investment Growth

John invests $10,000 today in a diversified portfolio that he expects to yield an average annual return of 8%, compounded quarterly. How much will his investment be worth in 20 years?

  • Calculation Type: Future Value (FV)
  • Present Value (PV): $10,000
  • Annual Interest Rate (r): 8% (0.08)
  • Number of Periods (t): 20 years
  • Compounding Frequency (n): 4 (Quarterly)

Using the FV formula: FV = $10,000 * (1 + (0.08/4))^(4*20)

Result: John's investment is projected to grow to approximately $48,754.33 in 20 years.

Interpretation: This projection helps John visualize the long-term growth potential of his investment. It underscores the importance of starting early and staying invested to benefit from compounding returns. The total interest earned would be $38,754.33 ($48,754.33 – $10,000).

How to Use This Time Value of Money Calculator

Our Time Value of Money calculator is designed for simplicity and accuracy. Follow these steps to get your results:

  1. Select Calculation Type: Choose whether you want to calculate the "Future Value (FV)" of a current sum or the "Present Value (PV)" of a future sum using the dropdown menu.
  2. Enter Present Value (PV) or Future Value (FV):
    • If calculating FV, enter the amount you have now (your initial investment).
    • If calculating PV, enter the amount you want to have in the future.
  3. Input Annual Interest Rate: Enter the expected annual rate of return or interest rate as a percentage (e.g., 5 for 5%).
  4. Specify Number of Periods: Enter the total number of years for the investment or loan.
  5. Select Compounding Frequency: Choose how often the interest will be compounded (Annually, Semi-Annually, Quarterly, Monthly, or Daily). This significantly impacts the final result due to the power of compounding.
  6. Click "Calculate": The calculator will instantly display the primary result (either FV or PV), along with key intermediate values like the Present Value, Future Value, Total Interest Earned, and the Effective Annual Rate (EAR).

Reading Your Results

The calculator provides several key outputs:

  • Primary Result: This is the main value you asked the calculator to find (either FV or PV). It's highlighted for easy visibility.
  • Present Value (PV) / Future Value (FV): Shows the value at the opposite end of the time spectrum from your primary input.
  • Total Interest Earned: The total amount of growth generated by the interest over the specified periods.
  • Effective Annual Rate (EAR): The true annual rate of return, accounting for compounding. This is useful for comparing different investment options.

Decision-Making Guidance

Use these results to make informed financial decisions:

  • Investment Planning: Estimate potential growth to set realistic savings goals.
  • Loan Evaluation: Understand the total cost of borrowing money over time.
  • Project Assessment: Compare the present value of future cash flows to the initial investment cost.

Remember that the results are based on the inputs provided. Fluctuations in interest rates or actual investment returns can alter the final outcome. Always consider factors like inflation and taxes for a more complete financial picture.

Key Factors That Affect Time Value of Money Results

Several critical factors influence the outcome of any Time Value of Money calculation. Understanding these elements is vital for accurate financial planning and decision-making.

  1. Interest Rate (Rate of Return):

    This is arguably the most significant factor. A higher interest rate leads to faster growth of money over time. For FV calculations, a higher rate means your initial investment will grow substantially more. For PV calculations, a higher rate means you need less money today to reach a future goal because it will grow more quickly. Conversely, a lower rate reduces growth potential.

  2. Time Period (Duration):

    The longer the money is invested or borrowed, the greater the impact of compounding. A longer time horizon allows interest to earn interest, significantly amplifying the final value (FV) or reducing the present amount needed (PV). Even small differences in time can lead to large discrepancies in outcomes over decades.

  3. Compounding Frequency:

    Interest earned more frequently (e.g., daily vs. annually) will result in a higher future value because the interest starts earning returns sooner. The EAR reflects this effect. More frequent compounding leads to slightly higher returns due to the snowball effect of interest being added to the principal more often.

  4. Inflation:

    While not directly part of the standard TVM formula, inflation erodes the purchasing power of money. A calculated future value might be a larger nominal amount, but its real value (what it can buy) could be less if inflation is high. When planning for the future, it's essential to consider inflation-adjusted returns or use a "real" interest rate (nominal rate minus inflation rate).

  5. Fees and Taxes:

    Investment returns and loan costs are often reduced by management fees, transaction costs, and taxes. These reduce the net return or increase the effective cost. For example, taxes on investment gains decrease the actual amount you keep, while loan fees increase the overall cost of borrowing.

  6. Risk:

    The assumed interest rate often reflects the perceived risk of an investment. Higher-risk investments typically demand higher potential returns to compensate investors. If an investment underperforms its expected rate, the actual future value will be lower than projected. Conversely, lower-risk investments usually offer lower returns.

  7. Cash Flow Timing:

    For streams of payments (like annuities or loan repayments), the timing and amount of each cash flow are critical. Early cash flows have more time to grow (or cost more in interest) than later ones. This is why TVM calculations for annuities are more complex but essential for accurate valuation.

Frequently Asked Questions (FAQ)

  • What is the difference between nominal and effective interest rates?

    The nominal interest rate is the stated annual rate, while the effective interest rate (EAR) accounts for the effect of compounding within the year. The EAR will always be equal to or higher than the nominal rate if compounding occurs more than once a year.

  • Does the calculator account for inflation?

    The standard TVM calculation does not directly account for inflation. To estimate the future value in today's purchasing power, you would need to adjust the calculated FV by the expected inflation rate or use a "real" interest rate (nominal rate minus inflation rate) in the calculation.

  • What does "compounding" mean?

    Compounding is the process where interest earned on an investment is added to the principal amount, and subsequent interest calculations are based on the new, higher principal. This leads to exponential growth over time.

  • Can I use this calculator for loans?

    Yes, the TVM calculator can be used for loans. If you are calculating the future value of a loan amount, it shows how much you'll owe. If you are calculating the present value, it helps determine the current worth of future loan payments or the principal amount needed to pay off a loan.

  • What if the interest rate changes over time?

    This calculator assumes a constant interest rate throughout the entire period. For scenarios with changing interest rates, more complex financial modeling or specialized calculators would be needed, often involving breaking the calculation into segments with different rates.

  • How accurate are the results?

    The results are mathematically accurate based on the formulas and the inputs provided. However, the accuracy of the projection depends heavily on the accuracy of the input assumptions, particularly the interest rate, which can fluctuate in real-world investments.

  • What is the difference between periods and years?

    The calculator uses 'Number of Periods' for the total duration and 'Compounding Frequency' to determine how many times interest is applied per year. If you input '5' years and 'Annually' (frequency=1), the total periods are 5. If you input '5' years and 'Monthly' (frequency=12), the total compounding periods become 60 (5 * 12).

  • Can I calculate the value of an annuity with this tool?

    This specific calculator is designed for single lump-sum present and future value calculations. For annuities (a series of equal payments over time), you would need a dedicated annuity calculator, which uses different formulas to sum up the TVM of each individual payment.

Related Tools and Internal Resources

© 2023 Your Financial Website. All rights reserved.

var chartInstance = null; function validateInput(input, min, max) { var value = parseFloat(input.value); var errorSpanId = input.id + "Error"; var errorSpan = document.getElementById(errorSpanId); var isValid = true; if (isNaN(value)) { errorSpan.textContent = "Please enter a valid number."; errorSpan.classList.add('visible'); isValid = false; } else if (value max) { errorSpan.textContent = "Value out of range. Minimum: " + min + ", Maximum: " + max + "."; errorSpan.classList.add('visible'); isValid = false; } else { errorSpan.textContent = ""; errorSpan.classList.remove('visible'); } return isValid; } function updateCalculatorUI() { var calculationType = document.getElementById("calculationType").value; if (calculationType === "fv") { document.getElementById("fvInputs").style.display = "block"; document.getElementById("pvInputs").style.display = "none"; document.getElementById("primaryResultLabel").textContent = "Future Value (FV)"; document.getElementById("formulaText").innerHTML = "Formula Used: FV = PV * (1 + (r/n))^(nt)Where: PV = Present Value, FV = Future Value, r = Annual Interest Rate, n = Number of Compounding Periods per Year, t = Number of Years (Periods)."; } else { // pv document.getElementById("fvInputs").style.display = "none"; document.getElementById("pvInputs").style.display = "block"; document.getElementById("primaryResultLabel").textContent = "Present Value (PV)"; document.getElementById("formulaText").innerHTML = "Formula Used: PV = FV / (1 + (r/n))^(nt)Where: PV = Present Value, FV = Future Value, r = Annual Interest Rate, n = Number of Compounding Periods per Year, t = Number of Years (Periods)."; } // Clear results when UI changes document.getElementById("primaryResultValue").textContent = "–"; document.getElementById("primaryResultUnit").textContent = "–"; var resultItems = document.querySelectorAll("#resultsDisplay .result-item .value"); for (var i = 0; i < resultItems.length; i++) { resultItems[i].textContent = "–"; } document.getElementById("amortizationTableBody").innerHTML = ""; document.getElementById("amortizationTableContainer").style.display = "none"; if (chartInstance) { chartInstance.destroy(); chartInstance = null; } } function calculateTVM() { var calculationType = document.getElementById("calculationType").value; var pvInput = document.getElementById("presentValue"); var fvInput = document.getElementById("futureValue"); var interestRateInput = document.getElementById("interestRate"); var numberOfPeriodsInput = document.getElementById("numberOfPeriods"); var compoundingFrequencyInput = document.getElementById("compoundingFrequency"); var pv = parseFloat(pvInput.value); var fv = parseFloat(fvInput.value); var annualRate = parseFloat(interestRateInput.value) / 100; var years = parseFloat(numberOfPeriodsInput.value); var n = parseFloat(compoundingFrequencyInput.value); var isValid = true; isValid = validateInput(pvInput, -Infinity, Infinity) && isValid; isValid = validateInput(fvInput, -Infinity, Infinity) && isValid; isValid = validateInput(interestRateInput, 0, 100) && isValid; isValid = validateInput(numberOfPeriodsInput, 0, Infinity) && isValid; if (!isValid) { return; } var effectiveRate = Math.pow(1 + annualRate / n, n) – 1; var totalPeriods = n * years; var calculatedPV, calculatedFV, totalInterest; var primaryResultLabel = document.getElementById("primaryResultLabel"); if (calculationType === "fv") { calculatedPV = pv; calculatedFV = calculatedPV * Math.pow(1 + annualRate / n, totalPeriods); totalInterest = calculatedFV – calculatedPV; primaryResultLabel.textContent = "Future Value (FV)"; document.getElementById("primaryResultValue").textContent = formatCurrency(calculatedFV); document.getElementById("primaryResultUnit").textContent = "USD"; document.getElementById("resultsDisplay").children[1].querySelector('.value').textContent = formatCurrency(calculatedPV); document.getElementById("resultsDisplay").children[1].querySelector('.unit').textContent = "USD"; document.getElementById("resultsDisplay").children[2].querySelector('.value').textContent = formatCurrency(calculatedFV); document.getElementById("resultsDisplay").children[2].querySelector('.unit').textContent = "USD"; } else { // pv calculatedFV = fv; calculatedPV = calculatedFV / Math.pow(1 + annualRate / n, totalPeriods); totalInterest = calculatedFV – calculatedPV; primaryResultLabel.textContent = "Present Value (PV)"; document.getElementById("primaryResultValue").textContent = formatCurrency(calculatedPV); document.getElementById("primaryResultUnit").textContent = "USD"; document.getElementById("resultsDisplay").children[1].querySelector('.value').textContent = formatCurrency(calculatedPV); document.getElementById("resultsDisplay").children[1].querySelector('.unit').textContent = "USD"; document.getElementById("resultsDisplay").children[2].querySelector('.value').textContent = formatCurrency(calculatedFV); document.getElementById("resultsDisplay").children[2].querySelector('.unit').textContent = "USD"; } document.getElementById("resultsDisplay").children[3].querySelector('.value').textContent = formatCurrency(totalInterest); document.getElementById("resultsDisplay").children[3].querySelector('.unit').textContent = "USD"; document.getElementById("resultsDisplay").children[4].querySelector('.value').textContent = (effectiveRate * 100).toFixed(4) + "%"; document.getElementById("resultsDisplay").children[4].querySelector('.unit').textContent = ""; updateChart(calculatedPV, calculatedFV, years, n, annualRate); updateAmortizationTable(calculatedPV, calculatedFV, years, n, annualRate); } function updateEffectiveRate() { var annualRate = parseFloat(document.getElementById("interestRate").value) / 100; var n = parseFloat(document.getElementById("compoundingFrequency").value); var effectiveRate = Math.pow(1 + annualRate / n, n) – 1; document.getElementById("resultsDisplay").children[4].querySelector('.value').textContent = (effectiveRate * 100).toFixed(4) + "%"; } function formatCurrency(amount) { return amount.toLocaleString('en-US', { minimumFractionDigits: 2, maximumFractionDigits: 2 }); } function resetCalculator() { document.getElementById("calculationType").value = "fv"; document.getElementById("presentValue").value = "1000"; document.getElementById("futureValue").value = "1000"; document.getElementById("interestRate").value = "5"; document.getElementById("numberOfPeriods").value = "10"; document.getElementById("compoundingFrequency").value = "1"; // Clear errors var errorSpans = document.querySelectorAll('.error-message'); for (var i = 0; i < errorSpans.length; i++) { errorSpans[i].textContent = ""; errorSpans[i].classList.remove('visible'); } updateCalculatorUI(); calculateTVM(); // Recalculate with defaults } function copyResults() { var calculationType = document.getElementById("calculationType").value; var primaryResultLabel = document.getElementById("primaryResultLabel").textContent; var primaryResultValue = document.getElementById("primaryResultValue").textContent; var primaryResultUnit = document.getElementById("primaryResultUnit").textContent; var pvValue = document.getElementById("resultsDisplay").children[1].querySelector('.value').textContent; var fvValue = document.getElementById("resultsDisplay").children[2].querySelector('.value').textContent; var interestValue = document.getElementById("resultsDisplay").children[3].querySelector('.value').textContent; var earValue = document.getElementById("resultsDisplay").children[4].querySelector('.value').textContent; var assumptions = "Assumptions:\n"; assumptions += "- Calculation Type: " + (calculationType === "fv" ? "Future Value" : "Present Value") + "\n"; if (calculationType === "fv") { assumptions += "- Present Value (PV): " + pvValue + " " + document.getElementById("resultsDisplay").children[1].querySelector('.unit').textContent + "\n"; } else { assumptions += "- Future Value (FV): " + fvValue + " " + document.getElementById("resultsDisplay").children[2].querySelector('.unit').textContent + "\n"; } assumptions += "- Annual Interest Rate: " + document.getElementById("interestRate").value + "%\n"; assumptions += "- Number of Periods: " + document.getElementById("numberOfPeriods").value + " years\n"; assumptions += "- Compounding Frequency: " + document.getElementById("compoundingFrequency").options[document.getElementById("compoundingFrequency").selectedIndex].text + "\n"; var textToCopy = "— Time Value of Money Results —\n\n"; textToCopy += primaryResultLabel + ": " + primaryResultValue + (primaryResultUnit ? " " + primaryResultUnit : "") + "\n"; textToCopy += "Present Value (PV): " + pvValue + " USD\n"; textToCopy += "Future Value (FV): " + fvValue + " USD\n"; textToCopy += "Total Interest Earned: " + interestValue + " USD\n"; textToCopy += "Effective Annual Rate (EAR): " + earValue + "\n\n"; textToCopy += assumptions; navigator.clipboard.writeText(textToCopy).then(function() { alert("Results copied to clipboard!"); }, function(err) { console.error("Could not copy text: ", err); alert("Failed to copy results. Please copy manually."); }); } function updateChart(initialPV, finalFV, years, n, annualRate) { var ctx = document.getElementById('tvmChart').getContext('2d'); // Destroy previous chart instance if it exists if (chartInstance) { chartInstance.destroy(); } var labels = []; var dataSeries1 = []; // PV or FV depending on calculation type var dataSeries2 = []; // Interest Earned var periodLength = years / 10; // Aim for roughly 10 data points for the chart if (periodLength < 1) periodLength = 1; var step = Math.max(1, Math.round(years / 10)); // Ensure step is at least 1 year var currentPV = initialPV; var currentFV = finalFV; var calculationType = document.getElementById("calculationType").value; var chartTitle = calculationType === "fv" ? "Investment Growth (FV Calculation)" : "Investment Value (PV Calculation)"; document.getElementById("chartContainer").querySelector('h2').textContent = chartTitle; for (var year = 0; year <= years; year += step) { var currentTotalPeriods = n * year; var valueAtYear; var interestAtYear; if (calculationType === "fv") { valueAtYear = initialPV * Math.pow(1 + annualRate / n, currentTotalPeriods); interestAtYear = valueAtYear – initialPV; dataSeries1.push(valueAtYear); // Represents total value dataSeries2.push(interestAtYear); // Represents interest component } else { // pv calculation // For PV, we show the future value decreasing towards the present value valueAtYear = finalFV / Math.pow(1 + annualRate / n, (years – year) * n); interestAtYear = valueAtYear – (finalFV / Math.pow(1 + annualRate / n, years * n)); // Interest relative to PV dataSeries1.push(valueAtYear); // Represents the future value at 'year' from now dataSeries2.push(valueAtYear – (finalFV / Math.pow(1 + annualRate / n, years * n))); // Interest component relative to PV } labels.push("Year " + year); } // Ensure the final year is included if not perfectly hit by the step if (labels.length === 0 || parseInt(labels[labels.length – 1].split(' ')[1]) !== years) { var currentTotalPeriods = n * years; var valueAtYear; var interestAtYear; if (calculationType === "fv") { valueAtYear = initialPV * Math.pow(1 + annualRate / n, currentTotalPeriods); interestAtYear = valueAtYear – initialPV; dataSeries1.push(valueAtYear); dataSeries2.push(interestAtYear); } else { valueAtYear = finalFV / Math.pow(1 + annualRate / n, (years – years) * n); // This is just finalFV interestAtYear = valueAtYear – (finalFV / Math.pow(1 + annualRate / n, years * n)); dataSeries1.push(valueAtYear); dataSeries2.push(interestAtYear); } labels.push("Year " + years); } chartInstance = new Chart(ctx, { type: 'line', data: { labels: labels, datasets: [{ label: calculationType === "fv" ? 'Total Value (PV + Interest)' : 'Future Value Projection', data: dataSeries1, borderColor: 'rgb(0, 74, 153)', tension: 0.1, fill: false }, { label: 'Interest Earned', data: dataSeries2, borderColor: 'rgb(40, 167, 69)', tension: 0.1, fill: false }] }, options: { responsive: true, maintainAspectRatio: false, scales: { y: { beginAtZero: true, ticks: { callback: function(value, index, values) { return '$' + value.toLocaleString(); } } } }, plugins: { tooltip: { callbacks: { label: function(context) { var label = context.dataset.label || ''; if (label) { label += ': '; } if (context.parsed.y !== null) { label += new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' }).format(context.parsed.y); } return label; } } } } } }); } function updateAmortizationTable(initialPV, finalFV, years, n, annualRate) { var tbody = document.getElementById("amortizationTableBody"); tbody.innerHTML = ""; // Clear previous table data var calculationType = document.getElementById("calculationType").value; var tableData = []; var currentBalance; var totalInterestAccrued = 0; if (calculationType === "fv") { currentBalance = initialPV; for (var year = 1; year = 1; year–) { var interestForYear = currentBalance / Math.pow(1 + annualRate / n, n) * (Math.pow(1 + annualRate / n, n) – 1); // Interest earned backwards var startBalance = currentBalance / Math.pow(1 + annualRate / n, n); totalInterestAccrued = finalFV – startBalance; // Total interest is FV minus the calculated PV tableData.push({ period: year, startBalance: startBalance, interest: interestForYear, // This represents interest earned relative to the start balance for that year endBalance: currentBalance }); currentBalance = startBalance; } tableData.reverse(); // Show in chronological order } if (tableData.length > 0) { document.getElementById("amortizationTableContainer").style.display = "block"; for (var i = 0; i < tableData.length; i++) { var row = tbody.insertRow(); var cellPeriod = row.insertCell(); var cellStart = row.insertCell(); var cellInterest = row.insertCell(); var cellEnd = row.insertCell(); cellPeriod.textContent = tableData[i].period; cellStart.textContent = formatCurrency(tableData[i].startBalance); cellInterest.textContent = formatCurrency(tableData[i].interest); cellEnd.textContent = formatCurrency(tableData[i].endBalance); } } else { document.getElementById("amortizationTableContainer").style.display = "none"; } } // Initial calculation on page load document.addEventListener('DOMContentLoaded', function() { updateCalculatorUI(); calculateTVM(); });

Leave a Comment