Coast FIRE Calculator
Most people will work until they're 65. Not because they have to — but because nobody showed them the math.
There's a number that changes everything: the exact amount you need invested so your money covers your expenses forever. Every year you don't know it, you're trading time you'll never get back.
This calculator shows you that number — and exactly how many years until work becomes optional. Takes 30 seconds.
Your Results
Coast FIRE Calculator: stop saving, start coasting
Coast FIRE is the point where you stop actively saving for retirement — and let compound growth finish the job. Your portfolio is big enough today that, with zero new contributions, it grows to your full FIRE number by traditional retirement age.
Use this Coast FIRE calculator to find the exact number: how much you need invested right now so you can downshift, take the lower-stress job, or go freelance without wrecking your retirement.
How Coast FIRE works: pick your target retirement age, set your annual retirement spending, and the calculator works backwards to find today's coast number. The math: Coast number = (annual spending × 25) ÷ (1 + return)years. Every year you delay Coast FIRE, the number grows — because compounding has less time to work. Hit Coast FIRE 10 years earlier and you roughly halve the required portfolio.
Coast FIRE vs Standard FIRE: Standard FIRE means full early retirement — no job needed. Coast FIRE means optional work decades earlier: you still cover current expenses, but you never have to save another dollar toward retirement. It's the shortest path out of forced work.
How the FIRE calculator works
This calculator uses the 4% safe withdrawal rule — the cornerstone of the FIRE movement. Established by William Bengen in 1994 and confirmed by the Trinity Study: if you withdraw 4% of your portfolio in year one of retirement and adjust for inflation annually, your portfolio has historically survived 30+ years in 96% of scenarios.
Your FIRE number is your annual retirement spending divided by your withdrawal rate. At 4%, that's your annual expenses multiplied by 25. Once your invested portfolio reaches this number, you're financially independent — work becomes optional.
The calculator iterates year by year, growing your portfolio at the expected return and adding your annual savings, until it crosses your FIRE number.
Frequently asked questions
What is the FIRE number?
Your FIRE number is the total investment portfolio you need to retire early. It's your annual retirement expenses divided by your safe withdrawal rate. At 4%, your FIRE number is annual expenses × 25. If you spend $50,000/year, your FIRE number is $1,250,000.
What is the 4% rule?
The 4% rule states that you can safely withdraw 4% of your portfolio in year one of retirement, then adjust for inflation each year, with a high probability (around 96%) that your portfolio will last 30+ years. It was established by the 1994 Bengen study and confirmed by the 1998 Trinity Study. Some financial planners suggest 3.5% for early retirees planning for 40–50 year retirements.
What is Coast FIRE?
Coast FIRE means you have enough invested today that — without adding another dollar — compound growth will carry your portfolio to your FIRE number by traditional retirement age. You can "coast" by working just enough to cover current expenses, with no need to save more for retirement.
What is Barista FIRE?
Barista FIRE means semi-retiring with part-time work that covers some of your expenses. Because your part-time income reduces how much you need from your portfolio, your required portfolio is much smaller. Every $1 of part-time income reduces your required portfolio by $25 (at 4% SWR).
How much do I need to retire at 40?
To retire at 40, you need 25× your annual expenses (at 4% SWR). If you spend $50,000/year, you need $1,250,000. For a 50-year retirement, consider using 3.5% SWR instead — that's 28.5× your expenses, or $1,425,000 for $50K annual spending. The earlier you retire, the more conservative your withdrawal rate should be.
What return rate should I use?
The US stock market has returned approximately 10% annually before inflation (7% after inflation) over long historical periods. Most FIRE practitioners use 7% as a nominal return and 5% as a real (inflation-adjusted) return. This calculator uses nominal returns by default — set it to 5% if you want inflation-adjusted projections.
Escape the 9-5 with FIRE
You just ran the numbers. Now here's everything you need to actually hit them.
Most people know they should save more. They don't know exactly how much to save, where to put it, or which legal tax moves shave years off their timeline. This book closes that gap — in 30 pages, no fluff.
- The savings rate table — see exactly how many years you can cut by saving 10% more
- Coast & Barista FIRE — the two paths most people overlook that get you out years earlier
- The Double Effect — why every spending cut does two jobs at once and why it beats a raise
- The tax stack — 401k → HSA → Roth Ladder, in the exact order that saves $20–50k over your career
- Sequence of returns risk — the one thing that can wreck a perfect plan, and how to protect against it
- One More Year Syndrome — the trap that keeps people working five years past their number
One decision from this book — adjusting your savings rate by 10%, or starting a Roth conversion ladder — is worth more than 1,000× the price.
Instant PDF download.