Financial Independence, Retire Early: your FIRE number from annual spending and withdrawal rate, years to reach it, and withdrawal-rate sensitivity.
Default 4% — the classic '4% rule'. It is a planning guideline from historical US data, not a guarantee; see the sensitivity figures.
Your FIRE number
How to use this tool
What you expect to spend a year in retirement, in today's money.
What is already invested and what you add each year.
7% and 4% are common planning defaults — change them to stress-test.
Compare the FIRE number at 3% and 5% before treating any one figure as your target.
Formula & worked example
Spending $40,000 a year at a 4% withdrawal rate gives a FIRE number of $1,000,000. At 3% the same spending needs $1,333,333; at 5% it needs $800,000. Saving $50,000 a year at 7% from zero reaches $1,000,000 in about 13 years.
Limitations — read this before you rely on it
A planning illustration, not a retirement plan. The 4% rule comes from historical US stock/bond data (Trinity study era) and may not hold for other countries, long retirements, or high-fee portfolios. It assumes smooth returns, ignores taxes, fees, inflation changes, healthcare costs and sequence-of-returns risk — retiring into a market crash is far riskier than the average suggests. Consider professional advice for real retirement decisions.
Frequently asked questions
Annual spending divided by your safe withdrawal rate. At 4%, spending $40,000 a year needs $1,000,000 invested — 25 times annual spending.
A guideline that a retiree can withdraw 4% of a portfolio in the first year (then inflation-adjusted) with a high historical success rate over 30 years, based on US market history. It is not a guarantee.
Because the withdrawal rate is the most uncertain input. A 1-point change moves the target by 25%: at 3% you need a third more saved; at 5% a fifth less, with much higher failure risk.
Not necessarily. Many pursue ' Coast FIRE' (enough saved that growth alone reaches the target) or 'Barista FIRE' (part-time work covering some spending), which need far less than full FIRE.
The risk that poor returns early in retirement deplete the portfolio before good years arrive. Two retirees with the same average return can have very different outcomes depending on the order of returns.