Calculator
Find the exact amount you need invested to coast to your full FIRE number — with no further savings required.
The calculation has three steps:
Once your portfolio hits your Coast FIRE number, you can stop saving entirely. The market does the rest.
7% is the approximate historical average return of a diversified US stock portfolio after inflation. 4% is the Trinity Study safe withdrawal rate — the amount you can withdraw annually with a high probability of not outliving your money over 30 years. Starting points, not guarantees.
This calculator uses your full annual expenses to derive your FIRE target. If you expect Social Security income in retirement, your actual portfolio target may be lower — because SS typically covers 30–50% of expenses for average earners. Including it would produce a smaller Coast FIRE number and an earlier coast date. The tradeoff: SS estimates depend on your claimed earnings history, your claiming age (62 vs. 70 produces roughly a 70% difference in monthly benefit), and whether the Social Security trust fund remains fully funded. The trust fund is projected to be depleted by the mid-2030s, which would trigger an automatic ~23% benefit reduction without Congressional action. Enter your full expenses here for the conservative (portfolio-only) calculation. Check your actual SS estimate at ssa.gov/my-account.
This calculator is for educational purposes only. It assumes constant returns, no Social Security income, and does not account for taxes, inflation variability, or sequence of returns risk. Consult a licensed financial advisor before making significant financial decisions.