Retirement Withdrawal Calculator

It depends on four things: how big your nest egg is, how much you withdraw, how that withdrawal grows with inflation, and what your portfolio earns. This calculator runs the year-by-year arithmetic: each year your balance earns its return, then you take out that year’s withdrawal, which a cost-of-living adjustment lifts a little each year. When the rising withdrawal finally outpaces the growth, the balance falls to zero — and that year is your answer. A 4% starting withdrawal on a portfolio earning ~5% real often stretches past 40 years; push the withdrawal to 6% and it can empty in roughly 20.

The 4% rule comes from William Bengen’s 1994 research and the Trinity study: historically, retirees who withdrew 4% of their portfolio in year one and raised that dollar amount with inflation each year rarely ran out of money over a 30-year retirement. It’s a useful rule of thumb, not a guarantee. Critics point out it was calibrated to 30-year horizons and specific U.S. market history; early retirees planning for 40–50 years, or anyone retiring into a poor decade of returns, may want a more conservative 3–3.5% starting rate.

It’s the danger that a string of bad returns early in retirement does far more damage than the same returns later — because you’re selling assets to fund withdrawals while prices are down, locking in losses you can’t recover from. Two retirees with identical average returns can have wildly different outcomes depending on the order those returns arrive. This calculator uses a single constant return, so it cannot show that risk; treat the result as the smooth-average case and build in a margin of safety.

To keep your spending power steady. If you withdraw a flat $40,000 every year, inflation quietly erodes what it buys — $40,000 two decades in might feel like $25,000 today. The cost-of-living adjustment (COLA) raises your dollar withdrawal by the inflation rate each year so your real lifestyle holds constant. The trade-off is that a rising withdrawal drains the portfolio faster than a flat one, which is exactly why a higher inflation assumption shortens how long the money lasts.

No — it models a single investment portfolio drawn down on its own. Real retirement income usually stacks several sources: Social Security, a possible pension, and taxable withdrawals all interact, and taxes take a bite from traditional-account withdrawals. Those generally make your portfolio last longer than this shows, because outside income covers part of your spending. Use this for the core intuition of how a balance depletes, then layer in your other income separately.

They’re mirror images. The retirement / FIRE calculator is about accumulation — given what you save, when do you reach your number? This one is about decumulation — given the number you’ve already got, how long does it last while you spend it down? Coast FIRE sits in between: whether what you’ve invested today will grow to your number by retirement with no further saving.