Calculate the Internal Rate of Return

.irr-container { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif; max-width: 800px; margin: 20px auto; padding: 25px; border: 1px solid #e1e1e1; border-radius: 12px; background-color: #ffffff; box-shadow: 0 4px 15px rgba(0,0,0,0.05); color: #333; } .irr-container h2 { color: #1a202c; text-align: center; margin-bottom: 25px; font-size: 1.8rem; } .irr-input-group { margin-bottom: 15px; } .irr-input-group label { display: block; margin-bottom: 6px; font-weight: 600; font-size: 0.95rem; color: #4a5568; } .irr-input-group input { width: 100%; padding: 12px; border: 1px solid #cbd5e0; border-radius: 6px; box-sizing: border-box; font-size: 1rem; transition: border-color 0.2s; } .irr-input-group input:focus { border-color: #4299e1; outline: none; box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.2); } .irr-button { width: 100%; background-color: #2b6cb0; color: white; border: none; padding: 15px; border-radius: 6px; font-size: 1.1rem; font-weight: bold; cursor: pointer; transition: background-color 0.2s; margin-top: 10px; } .irr-button:hover { background-color: #2c5282; } .irr-result { margin-top: 25px; padding: 20px; border-radius: 8px; background-color: #f7fafc; text-align: center; display: none; } .irr-result h3 { margin: 0; color: #2d3748; font-size: 1.2rem; } .irr-value { font-size: 2.2rem; font-weight: 800; color: #2b6cb0; margin: 10px 0; } .irr-interpretation { font-size: 0.9rem; color: #718096; line-height: 1.4; } .irr-article { margin-top: 40px; line-height: 1.7; color: #2d3748; } .irr-article h3 { color: #1a202c; margin-top: 25px; border-bottom: 2px solid #edf2f7; padding-bottom: 10px; } .irr-article p { margin-bottom: 15px; } .irr-example { background: #f0f4f8; padding: 15px; border-left: 4px solid #2b6cb0; margin: 20px 0; border-radius: 0 6px 6px 0; }

Internal Rate of Return (IRR) Calculator

Calculated IRR

0.00%

What is the Internal Rate of Return (IRR)?

The Internal Rate of Return (IRR) is a financial metric used by investors and businesses to estimate the profitability of potential investments. It is technically the discount rate that makes the net present value (NPV) of all cash flows from a particular project equal to zero.

In simpler terms, if you invest money today, the IRR is the annual percentage rate of return that your investment is expected to generate over its lifetime. The higher the IRR, the more desirable the investment.

How to Interpret IRR Results

IRR is usually compared against a company's "Hurdle Rate" or cost of capital. If the IRR exceeds the cost of capital, the project is generally considered a good investment. If it is lower, the project might result in a loss of value for the stakeholders.

Practical Example:
Imagine you invest $10,000 to start a small business. Over the next three years, the business earns you $4,000, $4,500, and $5,000 respectively. Your IRR would be roughly 16.23%. This means your $10,000 investment grew at an effective annual rate of 16.23%.

The Math Behind the Calculation

Since IRR is the rate where NPV equals zero, the formula is:

0 = NPV = Σ [ CashFlowt / (1 + IRR)t ]

This calculator uses a numerical iteration method (the Newton-Raphson method) to solve for IRR, as there is no direct algebraic formula to calculate it when dealing with multiple periods.

function calculateIRR() { var initial = parseFloat(document.getElementById('initialCost').value); var f1 = parseFloat(document.getElementById('flow1').value) || 0; var f2 = parseFloat(document.getElementById('flow2').value) || 0; var f3 = parseFloat(document.getElementById('flow3').value) || 0; var f4 = parseFloat(document.getElementById('flow4').value) || 0; var f5 = parseFloat(document.getElementById('flow5').value) || 0; var resultBox = document.getElementById('irrResultBox'); var display = document.getElementById('irrDisplay'); var status = document.getElementById('irrStatus'); if (isNaN(initial) || initial <= 0) { alert("Please enter a valid initial investment amount."); return; } var cashFlows = [-initial, f1, f2, f3, f4, f5]; // Newton-Raphson implementation var guestRate = 0.1; // 10% initial guess var maxIterations = 1000; var precision = 0.00001; for (var i = 0; i < maxIterations; i++) { var npv = 0; var derivativeNpv = 0; for (var t = 0; t 0) { derivativeNpv -= (t * cashFlows[t]) / Math.pow(1 + guestRate, t + 1); } } var newRate = guestRate – (npv / derivativeNpv); if (Math.abs(newRate – guestRate) 15) { status.innerText = "This represents a strong potential return on investment."; } else if (finalIrr > 0) { status.innerText = "This is a positive return, but compare it against your cost of capital."; } else { status.innerText = "The investment is currently showing a negative or zero internal rate of return."; } return; } guestRate = newRate; } display.innerText = "N/A"; status.innerText = "Could not converge on a solution. Please check your cash flow inputs."; resultBox.style.display = "block"; }

Leave a Comment