function calculateRetirement() {
var currAge = parseFloat(document.getElementById('currAge').value);
var retAge = parseFloat(document.getElementById('retAge').value);
var currSav = parseFloat(document.getElementById('currSav').value);
var monCont = parseFloat(document.getElementById('monCont').value);
var retRate = parseFloat(document.getElementById('retRate').value) / 100;
var postRetRate = parseFloat(document.getElementById('postRetRate').value) / 100;
var monSpend = parseFloat(document.getElementById('monSpend').value);
var infRate = parseFloat(document.getElementById('infRate').value) / 100;
if (isNaN(currAge) || isNaN(retAge) || isNaN(currSav) || retAge 0) {
fvCont = monCont * ((Math.pow(1 + monthlyRate, monthsToRetire) – 1) / monthlyRate);
} else {
fvCont = monCont * monthsToRetire;
}
var totalAtRetirement = fvCurrent + fvCont;
// Inflation Adjusted Spending Need
var monthlySpendAtRetire = monSpend * Math.pow(1 + infRate, yearsToRetire);
// How long will it last? (Drawing down an annuity)
var monthlyPostRate = postRetRate / 12;
var monthsLast = 0;
var tempBalance = totalAtRetirement;
// Loop to estimate months until depletion (simple drawdown)
while (tempBalance > 0 && monthsLast 0) monthsLast++;
}
var yearsLast = Math.floor(monthsLast / 12);
var remainingMonths = monthsLast % 12;
document.getElementById('retirementResult').style.display = 'block';
document.getElementById('totalSavings').innerText = '$' + totalAtRetirement.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 0});
document.getElementById('adjustedSpend').innerText = '$' + monthlySpendAtRetire.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 0});
var longevityMsg = "";
if (monthsLast >= 1200) {
longevityMsg = "Great news! Your savings are projected to last indefinitely based on your post-retirement return rate.";
} else if (yearsLast > 0) {
longevityMsg = "Based on your spending, your nest egg will last approximately " + yearsLast + " years and " + remainingMonths + " months (until age " + (retAge + yearsLast) + ").";
} else {
longevityMsg = "Warning: Your projected savings may not cover your desired monthly spending. Consider increasing contributions or extending your retirement age.";
}
document.getElementById('longevityMessage').innerText = longevityMsg;
}
Understanding Your Retirement Savings Strategy
Planning for retirement is one of the most significant financial journeys you will undertake. The Retirement Savings Calculator is designed to help you visualize how your current savings habits, investment returns, and inflation will impact your lifestyle in your golden years.
Key Variables in Retirement Planning
To get the most accurate results, it is important to understand the factors at play:
Compound Interest: The "Pre-Retirement Return" represents how much your investments grow while you are still working. Even a 1% difference in returns can result in hundreds of thousands of dollars over 30 years.
The Impact of Inflation: A dollar today will not buy the same amount of goods 20 years from now. This calculator adjusts your "Desired Monthly Income" by the inflation rate to show what that spending power looks like at the moment of your retirement.
Post-Retirement Return: Most retirees shift to more conservative investments (like bonds or fixed-income) once they stop working. This rate is typically lower than your accumulation rate but still vital for making your money last.
Example Scenario: The Power of Starting Early
Imagine Sarah, a 30-year-old with $25,000 in savings. She plans to retire at 65. If she contributes $500 monthly with a 7% annual return, she will retire with approximately $1.15 million. However, if she waits until age 40 to start those monthly contributions, her nest egg at 65 drops to roughly $515,000. This "cost of waiting" highlights why early planning is essential.
How to Close the Retirement Gap
If your results show that your savings won't last as long as you hope, consider these three levers:
Increase Monthly Contributions: Even an extra $100 a month can drastically change your outcome due to compounding.
Delay Retirement: Working just two or three years longer allows your portfolio more time to grow and reduces the number of years you need to draw from it.
Adjust Your Spending: Re-evaluating your desired retirement lifestyle can lower the "burn rate" of your nest egg.
Disclaimer: This calculator provides estimates for educational purposes only. Market returns are never guaranteed, and taxes (such as 401k withdrawals or capital gains) are not included in these calculations. Consult with a certified financial planner for personalized advice.