What is Coast FIRE?
FIRE stands for "financial independence, retire early." Your FIRE number is the amount of invested money that can fund your retirement spending indefinitely. Coast FIRE is a halfway point: you've saved enough that, even if you never add another dollar, compound growth will carry your portfolio to your FIRE number by your retirement age.
Once you're there, you still work, but only to cover current expenses. That can mean a lower-stress job, part-time work, or a career change, without putting retirement at risk.
The formulas
With a 4% withdrawal rate, the FIRE number is 25 times your yearly spending. Everything here is in today's dollars, which is why the calculator uses a return after inflation.
Example
You're 30, plan to retire at 65, and want $50,000 a year in today's dollars. At a 4% withdrawal rate your FIRE number is $1,250,000. With a 5% return after inflation and 35 years to grow, you need $226,613 invested today to coast. If you have $80,000 now (35% of the way) and add $1,000 a month, you reach Coast FIRE around age 48 and 8 months. After that, you could stop contributing entirely and still hit $1.25 million by 65.
Things to keep in mind
- Returns aren't smooth. A bad decade right before retirement can delay your plan. Many people add a buffer by using a lower return or a 3.5% withdrawal rate.
- Coasting doesn't mean spending the portfolio. You still need income for current costs, health insurance, and taxes.
- Retiring before 59½ takes planning, since most retirement accounts charge a 10% penalty on early withdrawals, with some exceptions.
- Social Security lowers the amount your savings need to cover once it starts. Check the claiming age with our break-even calculator.
Frequently asked questions
What is a Coast FIRE number?
It's the amount you need invested today so that, with no more contributions, compound growth reaches your full FIRE number by your planned retirement age. It equals your FIRE number divided by (1 + real return) raised to the number of years until retirement.
How do I calculate my FIRE number?
Divide the yearly spending your savings must cover by your withdrawal rate. At a 4% withdrawal rate, that's 25 times your yearly spending. Subtract expected Social Security from spending first if you'll receive it.
What return should I use for Coast FIRE?
Use a return after inflation, since the goal is in today's dollars. Many people use 4% to 6% for a stock-heavy portfolio. A lower number builds in a safety margin.
What's the difference between Coast FIRE and Barista FIRE?
Coast FIRE means your savings can grow to your full retirement goal without new contributions, so you only work to cover current bills. Barista FIRE usually means you've left full-time work and use part-time income to cover part of your spending while your portfolio covers the rest.
Should I include Social Security in Coast FIRE?
If you expect to receive it, including it lowers the amount your savings need to cover. Some people leave it out as a safety margin, especially if they plan to retire long before Social Security starts.
Estimates only, using a constant return after inflation. Real returns vary and can be negative. Taxes on withdrawals and fees are not included unless reflected in your return and spending. Not financial advice. Last updated October 1, 2026.