How Long Will My Money Last in Retirement Calculator

Free how long will my money last in retirement calculator: portfolio, first-year withdrawal, COLA, real return, year-step depletion or 80-year cap, balance trail bars, sensitivity charts, scenarios—plus guide. Not investment advice.

How Long Will My Money Last in Retirement? | Withdrawal Sandbox

Sequence risk is missing: This is a smooth deterministic year-step model—same real return every year, withdrawals that rise smoothly. Real markets jump, taxes change, and healthcare shocks exist. Use the output to ask better questions of a fiduciary planner, not to pick a retirement date alone.

Summary: Enter starting portfolio, first-year withdrawal, an annual COLA on withdrawals (%), and a single expected real return (% per year after inflation, simplified). The tool simulates year-end balances until funds are depleted or an 80-year horizon cap—then shows how many full years the plan lasted, a balance-by-year bar trail, sensitivity charts, and scenario rows.

Mechanics (short)
  • Each year: balance grows by the real return, then the year’s withdrawal is subtracted.
  • Withdrawals grow by the COLA percent before the next year.
  • Depletion = first year-end where balance ≤ 0 (partial-year interpolation is not applied; see guide).
  • If balance never falls to zero within 80 years, the chart shows the trail and the headline reads 80+ (not depleted in window).

How long will my money last in retirement? (constant-real-return sandbox)

This is the spreadsheet column your robo-advisor hides behind Monte Carlo—useful for order-of-magnitude and sensitivity, dangerous as a promise.

Plan inputs

Cost-of-living increases applied to the withdrawal line.

Single average after inflation—educationally simple, not historical backtest.

Years lasted, ending balance trail, and charts will appear here.

For Social Security timing, RMDs, and why bear markets hate new retirees, read Longevity math without the cruise brochure certainty below.