CoastFIRECalculator.us is a free, privacy-first financial education tool for US retirement planners. No sign-up. No ads that track you. Just math that works.
We believe everyone deserves access to clear, honest financial planning tools. Our mission is to make Coast FIRE concepts easy to understand and calculate for everyday Americans — without jargon, paywalls, or misleading claims.
All calculations happen in your browser using client-side JavaScript. We never collect, store, or transmit your financial data to any server. Your numbers stay on your device — always.
We use the standard Present Value compound interest formula used by professional financial planners. Our default 7% return rate is based on the S&P 500's historical long-term average (after inflation).
This tool is and will always be free to use. We believe financial planning resources should be accessible to everyone regardless of income. No premium tiers, no locked features.
Our Coast FIRE Calculator uses two well-established financial formulas:
Step 1 — FIRE Target = Annual Retirement Expenses ÷ Safe Withdrawal Rate
Step 2 — Coast FIRE Number = FIRE Target ÷ (1 + Annual Return)^Years to Retirement
The second formula is the Present Value (PV) formula — the same one used in every finance textbook and CFA curriculum. It answers: "How much do I need invested TODAY, at a given growth rate, to reach a future goal?"
CoastFIRECalculator.us is an independent educational tool. It is not affiliated with any financial institution, government agency, or investment platform. All calculations are estimates based on mathematical formulas and assumed constant return rates.
Past market performance does not guarantee future results. Actual investment returns will vary due to market conditions, fees, taxes, and other factors. This tool does not constitute financial, legal, or tax advice. Please consult a qualified financial advisor for personalized guidance.