Savings rate calculator
The share you keep, weighed against the years it costs. Your salary never enters the arithmetic — and that is the entire point.
Years to independence
31.9
Saving to the ledger is an Assay Master feature — see membership.
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The whole table
Years from zero to financial independence, at every savings rate. Change the return or withdrawal rate above and the table restrikes.
| Savings rate | Years to FI |
|---|---|
| 10% | 51.4 |
| 15% | 42.8 |
| 20% | 36.7 |
| 25% | 31.9 |
| 30% | 28.0 |
| 35% | 24.6 |
| 40% | 21.6 |
| 45% | 19.0 |
| 50% | 16.6 |
| 55% | 14.4 |
| 60% | 12.4 |
| 65% | 10.5 |
| 70% | 8.8 |
| 75% | 7.1 |
| 80% | 5.6 |
| 85% | 4.1 |
| 90% | 2.7 |
Why the salary cancels
years = ln(1 + T·r ÷ PMT) ÷ ln(1+r) T ÷ PMT = ((1−s) ÷ swr) ÷ s Start from zero and the only thing that matters is the ratio of the target to the annual contribution. Save a fraction s of take-home and you spend the rest, so the target is (1−s) × income ÷ the withdrawal rate, and the contribution is s × income. Income sits in both, so it divides out and disappears from the answer entirely.
This is the argument the FIRE movement rests on, and it survives contact with the algebra rather than needing to be taken on faith. A raise you spend in full moves nothing. A raise you save in full moves everything — not because the money is larger, but because the rate went up.
Assumptions on the counter
- Starting from zero invested. Any existing balance shortens this; the FIRE calculator takes one.
- Savings rate measured on take-home pay, and held constant for the whole run.
- A real return net of inflation, compounded annually, contributions at year-end.
- Spending in retirement matches spending now. Many things change at retirement — commuting stops, healthcare does not.
Questions people ask
What savings rate do I need to retire early?
At a 5% real return and a 4% withdrawal rate, saving 25% of take-home pay takes about 32 years from zero; 50% takes about 17; 70% takes about 9. The curve is steep at the low end — the first ten points of savings rate you add are worth far more years than the last ten.
Why does my salary not appear in this calculator?
Because it cancels. Your target is your spending divided by the withdrawal rate, and your spending is whatever fraction of income you did not save — so both the target and the contribution scale with income, and the ratio between them does not. Two people saving 50% of take-home reach independence in the same number of years whether they earn $60,000 or $600,000.
Is savings rate measured on gross or net income?
Net — take-home pay. Measuring against gross counts money you never received and quietly inflates the rate by whatever you pay in tax. Employer 401(k) matching is a genuine grey area; the tidiest treatment is to add the match to both your income and your savings.
Does this account for money I have already saved?
No — this page deliberately starts from zero, because that is what makes the salary cancel and the table universal. If you already have a balance, use the FIRE calculator instead; it takes your current portfolio and shortens the timeline accordingly.