FIRE Calculator

Your FIRE number is the portfolio size at which your chosen withdrawal rate covers your annual spending: annual spending ÷ withdrawal rate. On $50,000/yr spending and a 4% withdrawal rate, that is $1,250,000. Change either input and the number moves with it — it is not a fixed target.

Coast FIRE is the amount you'd need invested today so that, with zero further contributions, investment growth alone carries it to your FI number by a target retirement age. It is your FI number discounted backward at your expected return: FI number ÷ (1 + return)^years. On the worked example (FI number $1,250,000, 5% real return, 35 years to age 65), that's about $226,613 — someone who has already saved that much could stop contributing and still reach their FI number by 65 on growth alone.

4% is a commonly cited rule of thumb, not a guarantee. Its applicability depends on a fixed withdrawal rate, a specific historical stretch of market returns, and no major fee drag — none of which is certain to repeat. This calculator treats it, like your expected return, as an assumption you can change, and the result is a projection: it ignores taxes, fees, and the order gains and losses arrive in (sequence-of-returns risk), all of which can move your real number.

There is no single right answer — both are editable starting assumptions, not facts. A 5% real (after-inflation) return and a 4% withdrawal rate are common starting points for a diversified stock-and-bond portfolio, but your own risk tolerance, time horizon, and fees should set the inputs you actually use.

No. It projects a pre-tax portfolio balance at a constant real (after-inflation) return. Actual withdrawals are usually taxed, and the tax owed depends on account type (taxable, 401(k), Roth) and your situation, so your real after-tax spending power will differ from the raw numbers here.