About CoastFIRE.org

Why We Built This Site

CoastFIRE.org started with a simple frustration: most financial calculators online are either locked behind a signup form, cluttered with pop-ups, or too complicated for a quick "what if" question. We wanted a set of calculators that just work — no account, no spreadsheet, no spam.

Today the Site offers five free calculators built around the FIRE (Financial Independence, Retire Early) movement:

• Coast FIRE Calculator — find out how much you need invested today to "coast" to your retirement goal.
• FIRE Calculator — calculate your full FIRE number using the 4% rule.
• Retirement Calculator — project your retirement corpus and estimated monthly income.
• Investment Calculator — see how compound interest grows your money over time.
• SWR / 4% Rule Calculator — test different safe withdrawal rates against your portfolio.

How the Calculators Work

Every calculation runs directly in your browser using standard, well-documented financial formulas (compound interest and the 4% Safe Withdrawal Rate). Nothing you type is ever sent to a server or stored — see our Privacy Policy for details.

Our Approach

We are not financial advisors, and this Site is not a substitute for professional financial planning (see our Disclaimer). Our goal is simply to make the core math behind financial independence easy to explore, so you can understand the levers — savings rate, time, and return — that shape your own path.

Get in Touch

Have feedback, spotted a bug, or want to suggest a new calculator? We'd love to hear from you — visit our Contact page.