Nest Egg Longevity Calculator
See how many years a retirement nest egg lasts when you draw an inflation-adjusted income from it each year at an assumed rate of return.
How it works
Each year: balance = (balance − withdrawal) × (1 + return) · withdrawal grows by inflation · count years until the balance runs out
Longevity is a tug-of-war between growth adding to the pot and inflation-adjusted spending taking from it. If the return comfortably exceeds the withdrawal rate the balance can grow forever; if spending outpaces growth the pot erodes and eventually empties. Because withdrawals rise with inflation while a fixed nest egg does not, an income that looked safe in year one can accelerate the drawdown later — which is why the withdrawal rate, not the dollar amount, is the number to watch.
Worked example
A $750,000 nest egg with a $40,000 first-year withdrawal is a 5.33% initial rate. Earning 5% while withdrawals climb 2.5% a year, spending outruns growth, and the money lasts roughly 26 years. Trimming the first withdrawal to 4% ($30,000) would stretch it far longer.
Frequently asked questions
How does this relate to the 4% rule?
The 4% rule is a rough guideline that a 4% initial withdrawal, rising with inflation, historically lasted about 30 years. This tool lets you test any rate, return and inflation assumption to see the resulting lifespan directly.
Why does the money run out faster than I expect?
Because withdrawals grow with inflation every year while your return may not keep pace, the yearly shortfall widens over time. A gap that is small early on compounds, pulling the depletion date forward.
Does this account for market crashes?
No — it uses a single steady return. Real sequences of returns matter: a crash early in retirement is far more damaging than the same crash late, a risk this smooth model cannot show.
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Educational estimate, not investment advice. Markets involve risk of loss and future returns are never guaranteed.