Coast FIRE · Financial Independence
Most retirement tools tell you when you can stop working. We tell you when you can stop saving — and let compound growth carry you the rest of the way.
Everything on this site is educational. The calculators and numbers shown are illustrative — not a recommendation, not personalized financial planning, not a substitute for a qualified advisor. Your actual results will differ. Use the tools to think through scenarios, not to make decisions.
What this site is
Coast FIRE is the point at which your invested savings will grow to your full retirement number on their own — with no further contributions from you. Most people hit it in their 30s or 40s, often without realizing it. Once you're there, the rest of the equation changes: you can ease up on savings, take a lower-paying job you actually like, or just breathe.
That idea is simple. The hard part is knowing your actual number, watching it move as markets move, and understanding what to do once you hit it. That's what this site is for.
We publish three things: calculators that show the math with no black boxes, plain-English guides that cover the surrounding concepts (compounding, safe withdrawal rates, Social Security, lifestyle creep, geographic arbitrage), and a growing blog with real case studies and data. Everything runs in your browser — no accounts, no data sent to a server, no email list to escape.
The concept, the two phases, who it works for, and the math behind it. Start here if you're new.
Enter your age, target retirement age, expenses, and current savings. Get your Coast FIRE number and the gap.
Plug in assets, liabilities, and expenses. See how close you are to your full FIRE number as a percentage.
Coast FIRE fundamentals, Social Security strategy, investment allocation, common edge cases. Answers, not jargon.
Real numbers from real people: lifestyle creep, geographic arbitrage, Social Security timing, why starting early wins.
The Rule of 72, the math, and the comparison that makes the case for starting early stronger than any other argument.
How it works
There's no magic in the calculator — it's three steps you can do on a napkin.
Take your expected annual expenses in retirement and divide by your safe withdrawal rate. At 4% (the historical default from the Trinity Study), that's 25× your annual expenses. $50,000 a year in expenses means a $1,250,000 target.
Target retirement age minus your current age. That's how long compound growth has to work. 35 years is a long time — and that's the whole point.
Divide your full FIRE number by (1 + expected return)years. At 7% real return over 35 years, that's a divisor of about 10.7. The $1,250,000 target becomes a Coast FIRE number of about $117,000. If you have that much invested today, you can stop saving.
The math isn't aspirational — it's the same formula every retirement calculator uses, just applied earlier in the timeline. The full calculator walks through the formula with your numbers, and the 5-minute explainer goes deeper on why this works.
What the 4% rule actually means, where it came from, when it breaks, and how to choose a rate that fits your risk tolerance.
They look the same but aren't. A common error for small business owners pricing products.
The court process, what assets go through it, how long it takes, and what it costs.
Printable checklist for the Coast FIRE process: inputs to gather, calculations to run, decisions to make.
Build your annual-expenses estimate the right way. Tracks fixed, variable, and one-time categories.
Enter your monthly spending to estimate your annual expenses — the input the FIRE number depends on.