⏳ Portfolio Longevity
How long your corpus lasts and a sustainable withdrawal rate.
Once you've retired or reached FIRE, this calculator flips the question around: given a starting corpus and a withdrawal amount, how many years will your money actually last — and what withdrawal rate keeps it sustainable indefinitely?
It models sequential annual withdrawals against a corpus that continues to grow at your expected return, adjusting the withdrawal upward each year for inflation. The corpus depletes when withdrawals plus inflation outpace investment growth; the calculator finds that crossover year. It is the direct follow-on to Retirement Planning once you've stopped working, and the stress-test for a Financial Independence (FIRE) number.
A 2,00,00,000 corpus, with an initial withdrawal of 8,00,000/year (a 4% withdrawal rate), growing at 8% annually, and inflation at 6%, may last 30+ years — versus a corpus withdrawing at 6% initially, which could deplete in under 20 years.
Not adjusting withdrawals for inflation gives a falsely optimistic longevity number in year one but drastically understates real purchasing power lost over time. Sequence-of-returns risk (poor returns early in retirement) also matters more than average returns — this calculator uses a constant-return model, so treat results as a baseline, not a guarantee.
What it does
Simulates withdrawing from a retirement corpus year by year — with inflation-escalating withdrawals — to find how long it lasts and what you can safely withdraw.
When to use it
Use it to stress-test retirement: does the corpus survive your expected years in retirement?
Assumptions
- Withdrawals are taken at the start of each year and rise with inflation.
- The portfolio earns a constant return with no bad years sequenced at the start.
- No taxes or fees are subtracted.
The sustainable withdrawal rate is the honest number — if your plan needs more than a sustainable rate to survive, reduce spending or delay retirement rather than hoping for higher returns. Real-world drawdowns make the early years the danger zone, so stay conservative.