Retirement Withdrawal Rate Calculator with Inflation
Estimate how long your retirement portfolio will last by factoring in annual withdrawals, investment returns, and the crucial impact of inflation purchasing power erosion.
Enter your details above to see how long your retirement savings might last.
function calculateLongevity() {
// 1. Get input values using var as requested
var portfolioValueStr = document.getElementById('portfolioValue').value;
var initialWithdrawalStr = document.getElementById('initialWithdrawal').value;
var inflationRateStr = document.getElementById('inflationRate').value;
var returnRateStr = document.getElementById('returnRate').value;
// 2. Parse and validate inputs
var portfolio = parseFloat(portfolioValueStr);
var withdrawal = parseFloat(initialWithdrawalStr);
var inflationDec = parseFloat(inflationRateStr) / 100;
var returnDec = parseFloat(returnRateStr) / 100;
var resultDiv = document.getElementById('result');
if (isNaN(portfolio) || isNaN(withdrawal) || isNaN(inflationDec) || isNaN(returnDec) || portfolio <= 0 || withdrawal = portfolio) {
resultDiv.innerHTML = "Your initial withdrawal is greater than or equal to your entire portfolio. It will not last one year.";
return;
}
// 3. Simulation Logic
// We assume withdrawal happens at the BEGINNING of the year, then the remainder grows.
var balance = portfolio;
var currentAnnualWithdrawal = withdrawal;
var yearsLasted = 0;
var maxSimulationYears = 60; // Cap simulation to prevent infinite loops or unrealistic horizons
var depleted = false;
var initialWithdrawalPercentage = (withdrawal / portfolio) * 100;
for (var year = 1; year <= maxSimulationYears; year++) {
// Withdraw at start of year
balance = balance – currentAnnualWithdrawal;
if (balance < 0) {
depleted = true;
// It didn't last this full year.
yearsLasted = year – 1;
break;
}
// Growth on remaining balance for the year
balance = balance * (1 + returnDec);
// Increase withdrawal amount for the *next* year based on inflation
currentAnnualWithdrawal = currentAnnualWithdrawal * (1 + inflationDec);
yearsLasted = year;
}
// 4. Generate Output HTML
var outputHTML = "
Results Analysis
";
outputHTML += "
";
outputHTML += "Initial Withdrawal Rate: " + initialWithdrawalPercentage.toFixed(2) + "%";
if (depleted) {
outputHTML += "Your portfolio is estimated to last approximately: " + yearsLasted + " Years";
outputHTML += "The portfolio runs out of funds during year " + (yearsLasted + 1) + " due to withdrawals increasing with inflation.";
} else {
outputHTML += "Your portfolio is estimated to last: More than " + maxSimulationYears + " Years";
outputHTML += "At the end of " + maxSimulationYears + " years, your projected remaining balance is approx. " + new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD', maximumFractionDigits: 0 }).format(balance) + " (in future dollars).";
}
outputHTML += "
";
outputHTML += "Note: This simulation assumes withdrawals are taken at the beginning of each year, and the remaining balance grows at the specified investment return rate. Inflation increases the withdrawal amount annually.";
resultDiv.innerHTML = outputHTML;
}
Understanding Retirement Withdrawal Rates and Inflation Risk
Planning for retirement involves more than just hitting a savings goal number. The critical question is: how fast can you spend that money so you don't outlive your savings? This "Withdrawal Rate Calculator with Inflation" helps answer that question by simulating the lifespan of your portfolio under specific economic conditions.
Why Inflation Matters in Retirement
Many retirees make the mistake of planning for a fixed dollar withdrawal every year (e.g., taking out $50,000 annually). While this sounds simple, it ignores inflation. Over a 25 or 30-year retirement, the purchasing power of money drops significantly. To maintain the same standard of living you had in year one, your withdrawal amount needs to increase every year to keep up with the rising cost of goods and services.
This calculator adjusts your withdrawal amount upward annually based on the inflation rate you provide, offering a much more realistic view of portfolio longevity than a simple static calculator.
How to Use This Calculator
Initial Portfolio Value: The total amount of investable assets you have at the start of retirement.
First Year Withdrawal Amount: How much cash you need to take out in year one to cover expenses. This establishes your baseline standard of living.
Estimated Annual Inflation (%): The average rate at which you expect prices to rise. Historic averages often range between 2% and 3%, though periods of higher inflation do occur.
Estimated Annual Investment Return (%): The average annual growth rate you expect from your investment portfolio (stocks, bonds, etc.). This should be a realistic, long-term average.
The "Safe Withdrawal Rate" Concept
You may have heard of the "4% Rule," which suggests that withdrawing 4% of your portfolio in the first year, and then adjusting that dollar amount for inflation in subsequent years, has historically proven safe for a 30-year retirement horizon in many market scenarios. This calculator allows you to test that theory against your own numbers. If your initial withdrawal rate is significantly higher than 4% (e.g., 6% or 7%) and you factor in inflation, you will likely see the portfolio longevity drop dramatically below 30 years.
Use this tool to model different scenarios. See how lowering your initial withdrawal or achieving a slightly higher investment return impacts how long your nest egg lasts.