Savings rate calculator: years to FIRE
Captain Compound would like to know how fast you're going. Enter your take-home pay and savings rate, and this calculator estimates how many years until your investments reach your FIRE number. It is a very honest calculator. It has never once told anyone what they wanted to hear on purpose.
Illustration only. Constant assumptions you choose; real returns vary, and taxes, fees, raises and life events aren't modeled. Not a prediction or advice. CPA Warning Label: do not use the result to resign by email tonight.
Year-by-year projection
| Year | Start balance | Growth | Contribution | End balance |
|---|
How it works (no magic, we checked)
- Annual spending = take-home pay × (1 − savings rate). Annual saving = take-home pay × savings rate.
- FIRE number = annual spending ÷ withdrawal rate (at 4%, 25× spending).
- Each year: end balance = start balance × (1 + real return) + annual saving, with saving added at year end.
- Everything is in today's dollars because the return is a real (after-inflation) return.
- Assumes retirement spending equals current spending. Not modeled: taxes on withdrawals, fees, health insurance changes, Social Security, sequence-of-returns risk.
With $0 saved, a 5% real return and a 4% withdrawal rate, this calculator reproduces the table in Your savings rate decides your FIRE timeline (for example, 17 years at a 50% savings rate).
What to do this week
- Calculate your real savings rate from statements, not vibes.
- Try your number plus 5 percentage points and see how many years it saves.
- Automate that increase if the trade feels worth it.