Savings Rate to Years-to-FI Calculator
Your savings rate — not your income — is the number that actually determines how many years until financial independence. Enter your income and the % you save to see your own timeline, and how it shifts at other savings rates.
Years to FI at other savings rates
Same income, return and withdrawal rate — only the savings rate changes.
How this is calculated
Savings rate here means the share of after-tax income you save and invest, not a share of gross pay — spending is simply income minus savings, and your FIRE number is that spending divided by your withdrawal rate, same as the FIRE number calculator on this site.
Years to FI comes from a real month-by-month compounding simulation — monthly savings invested at your chosen return rate, compounding until the portfolio reaches the FIRE number — not a closed-form shortcut. This is the same simulation engine used by the FIRE number and Coast FIRE calculators, so results stay consistent across all three.
The reason savings rate dominates the result more than income does: a higher income raises both what you can save AND what you're used to spending, by default. Two people earning very different incomes but saving the same percentage reach financial independence in almost exactly the same number of years, because the math only cares about the ratio between what you keep and what you spend — not the absolute numbers.
The curve table holds income, return rate and withdrawal rate fixed and only changes the savings rate, isolating that one variable's effect — at a 5% real return and 4% withdrawal rate, this calculator's simulation lands within about half a year of the widely-cited reference figures from the 'Shockingly Simple Math' savings-rate table (e.g. roughly 17 years at a 50% savings rate, roughly 10.5 years at 65%), which is a reasonable cross-check given the reference table uses a slightly different compounding convention.
Frequently asked questions
Why does savings rate matter more than income?
Because your FIRE number scales with your spending, and a higher income only shortens your timeline if the extra income doesn't also raise your spending. Someone earning twice as much but saving the same percentage has a FIRE number twice as large too — the years-to-FI stays almost the same, since both the target and the yearly progress toward it doubled together.
What counts as 'income' here — gross or after-tax?
Use your after-tax, take-home income. The calculator splits that number into spending and savings; if you enter gross income instead, both your implied spending and your FIRE number will be overstated by roughly your tax rate.
Why do the reference figures for 50% and 65% savings rates differ slightly from other sources?
This calculator runs a real month-by-month simulation rather than the closed-form approximation some published tables use, and different tools make slightly different assumptions about when during the year contributions land. The two approaches land within roughly half a year of each other at the same assumptions — close enough to serve as a sanity check, not a discrepancy that changes the conclusion.
Does this work in any currency?
Yes — every figure here is just a number with no currency conversion built in. Enter income, portfolio and results in your own currency and they stay consistent throughout.
Sources
- Mr. Money Mustache — 'The Shockingly Simple Math Behind Early Retirement' (savings-rate-to-years reference table, 5% real return / 4% SWR assumption)
- Trinity Study (1998) and related safe-withdrawal-rate research — basis for the 4% withdrawal-rate convention used here
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Disclaimer
This tool provides an estimate for informational purposes based on the figures and return assumption you enter and isn't financial advice. It assumes a constant savings rate and return every year, which real income, spending and markets rarely deliver exactly — treat the result as a planning estimate, not a guarantee.
Last updated 2026-11-08.