Retirement Savings Calculator

Estimate how long your retirement savings will last based on your current balance, monthly income, and expenses.

The current amount in your retirement savings account.
The expected annual return on your savings (e.g., 4 for 4%).
Regular monthly income (e.g., Social Security, pensions).
Total monthly expenses including withdrawals from savings.

Your Results

Based on your inputs, here’s how long your savings will last:

Savings Duration
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Total Withdrawals
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Interest Earned
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Final Balance
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Retirement Savings Calculator

Planning for retirement means more than just saving—it’s about understanding how long your retirement savings will last once you begin using them. This Retirement Savings Calculator helps you estimate how many years your savings will sustain your lifestyle based on your starting balance, monthly income, expenses, and interest rate.

You can explore more similar tools on the Savings Calculators Index page to plan your financial future effectively.

Calculator Inputs

  • Retirement Savings Account Balance - The current amount in your retirement savings account or the amount you will deposit to start the retirement account.
  • Annual Interest Rate - The stated annual interest rate. This calculator compounds interest monthly. For example, an annual rate of 7% becomes a monthly rate of 0.583% (0.07/12). Interest is calculated at the end of each month after any withdrawals.
  • Monthly Income - Regular monthly income deposits such as Social Security payments, pensions, or other income that goes into this account.
  • Monthly Expenses - Your total monthly expenses that are withdrawn from this account. This should be higher than your monthly income for the calculation to be meaningful.

Example: If you have $75,000 at 4% interest with $1,800 monthly income, try entering $2,800 for expenses to see savings last 8 years and 1 month. Lower expenses to $2,550 to make savings last about 10 years and 1 month.

Understanding the Retirement Savings Calculator

This calculator is designed for retirees who have an existing savings balance and want to know how long their money will last once they start making withdrawals. It assumes you have a retirement savings account, receive a fixed monthly income (like social security), and have regular monthly expenses that may exceed that income.

Each month, your savings account earns interest and adjusts based on your deposits (income) and withdrawals (expenses). The calculator estimates how many months or years your savings will last before reaching zero.

How the Retirement Savings Calculator Works

The formula behind this tool compounds interest monthly and deducts net withdrawals at the end of each period.

Plain Text Formula:
Future Value = (Starting Balance × (1 + r)^t) + [(Monthly Income – Monthly Expenses) × (((1 + r)^t – 1) / r)]

Where:

  • r = monthly interest rate (annual rate ÷ 12)
  • t = number of months

The calculator iteratively determines when the Future Value = 0, meaning your savings are depleted.

For example, if your annual interest rate is 7%, the monthly rate used in the calculation is 0.07 / 12 = 0.00583 (or 0.583% per month).

You can also test different withdrawal amounts to see how small changes affect the duration of your savings.

Example: Estimating How Long Savings Will Last

Suppose you start with $75,000 in your retirement account earning 4% annual interest. You receive $1,800 in monthly income and spend $2,800 each month.

After entering these numbers, the calculator shows your savings will last approximately 8 years and 1 month.

If you reduce expenses to $2,550 per month, your savings extend to about 10 years and 1 month.

This helps you balance withdrawals with longevity—showing exactly how long your money will sustain your retirement.

Why Compound Interest Matters in Retirement Planning

Interest plays a major role in extending your retirement fund’s life. Even small percentage differences in annual return can change your results dramatically. The compounding effect means your savings grow faster when earnings are reinvested each month.

If you want to estimate how your money could grow over time before retirement, you can use the CAGR Calculator to determine the compound annual growth rate of your investments.

Tips to Make Your Savings Last Longer

  • Delay large withdrawals: Early large withdrawals can significantly shorten your savings life.
  • Reduce expenses: Even small monthly reductions can extend your savings by several years.
  • Seek higher yields (safely): Conservative investments that offer slightly higher interest rates can improve longevity.
  • Revisit your plan annually: Adjust inputs like expenses and returns to stay on track.

For a detailed analysis of how your retirement balance can grow, try the Future Value of Investment Account Calculator.

The Retirement Savings Calculator is a simple but powerful tool that answers a crucial question: How long will your savings last once you retire? By combining your income, expenses, and expected return, it provides a clear estimate so you can plan confidently.

Adjusting your spending or investment rate can make a big difference—sometimes turning an 8-year plan into a 10- or 12-year cushion. Use it as part of your broader retirement strategy to ensure your financial comfort lasts as long as you do.