FIRE Calculator — Financial Independence
Years to financial independence from your savings rate, your FIRE number at a 4% (or custom) withdrawal rate, FI age, coast FIRE, lean and fat variants and a savings-rate table — any currency.
| Savings rate | — |
|---|---|
| FIRE number (target portfolio) | — |
| Progress | — |
| FI age | — |
| Coast FIRE | — |
| Lean / Fat FIRE | — |
| If you saved 10% more of income | — |
| If spending were 10% lower | — |
Years to FI by savings rate (same income, spending = income − savings)
In short
FIRE number = annual spending ÷ safe withdrawal rate (25× spending at 4%). Years to reach it depend on the savings rate, not income: at a 5% real return, 25% saved takes about 32 years, 50% about 17 and 70% about 8.5. Someone spending 42,000 of a 70,000 take-home (40% saved) with 60,000 invested needs 1.05 million and gets there in about 20 years.
Who this is for: Anyone pursuing financial independence or early retirement who wants the timeline from their savings rate.
The FIRE arithmetic
- FIRE number = annual spending ÷ safe withdrawal rate. At 4% that is 25× spending; the portfolio then funds you indefinitely in most historical periods (3–3.5% is safer for very long retirements).
- Savings rate is everything: it sets both how fast the pot grows and how small the pot needs to be. At a 5% real return, 10% saved takes ~50 years, 25% ~32 years, 50% ~17 years, 70% ~8.5 years — regardless of income.
- Real return: all figures are in today's money, so use a return net of inflation (5% real ≈ 7.5% nominal at 2.5% inflation).
- Coast FIRE: once today's pot would grow to the target by 65 on its own, you only need to earn enough to cover spending.
- Lean / Fat: the same plan at 70% and 150% of your current spending — the range between frugal and comfortable.
- Tax on withdrawals, healthcare costs and sequence-of-returns risk are the real-world caveats; most planners add a buffer of 10–20% to the number.
See also: Retirement Savings Calculator.
Assumptions
- Savings = income − spending; FIRE number = (retirement spending − other income) ÷ withdrawal rate; years found by compounding the pot at the real return with annual contributions.
- Coast FIRE checks whether today's pot grows to the target by 65 without contributions.
- Lean = 70% and fat = 150% of retirement spending; table recomputes for savings rates of 10–70% with spending = income − savings.
Worked example
Savings rate 40% (28,000 a year). FIRE number 42,000 ÷ 4% = 1,050,000; 5.7% there. Reaching it takes about 20 years → age 50. Coast FIRE is not yet reached — about 190,000 would be needed today to coast to 65. Saving another 10% of income (35,000 a year) cuts it to about 18 years; lean FIRE (29,400 spending) comes in 16 years, fat (63,000) in 26.
Frequently asked questions
What savings rate do I need to retire in 15 years?
Roughly 50–55% at a 5% real return starting from zero; less if you already have a pot. The table shows the full curve for your inputs.
Is the 4% rule safe?
It survived most 30-year periods in US history; for a 40–50-year early retirement, 3–3.5% is the common recommendation, which raises the target by 15–30%.
Should I count my state pension?
Yes — enter it as other retirement income; it lowers the amount the portfolio must cover, though it starts at state pension age, not FI age.
Does this work outside the US?
Yes — it is currency-agnostic arithmetic. Only the tax treatment of withdrawals and the availability of state pensions differ.
What is my FIRE number?
25 times your annual spending at a 4% withdrawal rate; 28.6 times at 3.5%; enter other retirement income to reduce it.
What is coast FIRE?
Having enough invested that it will grow to your FIRE number by a normal retirement age without further contributions — you can then stop saving and only cover current spending.
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