Coast FIRE Planner

Coast FIRE Number Calculator

Find the one number that matters: how much you need invested today so compound growth carries you to retirement.

Your Coast FIRE number at 32$300,277

With this invested at 32, growth alone reaches $1,000,000 by 60, without adding another dollar.

FIRE number$1,000,000$40,000 a year at 4%
Real return used4.39%Over 28 years
Invested today$185,000$115,277 to go

You have $185,000: 62% of the way, $115,277 to go. See the month you'll reach it

In today's money. Educational only, not financial advice.

Coast FIRE number by age

The later you start, the more you need: each row is what you'd need invested at that age to coast to $1,000,000 by 60.

AgeYears to growCoast FIRE number
32 (you)28$300,277
3525$341,588
4020$423,450
4515$524,930
5010$650,730
555$806,678

How much the return matters

Your Coast FIRE number at 32 for different yearly returns before inflation.

5% return$509,293
6% return$390,575
7% return$300,277
8% return$231,421
9% return$178,783

Your numbers

$

In today's money.

$

Optional: to see how close you are.

Assumptions
%
%
%
%

How the Coast FIRE number is calculated

FIRE number = yearly spending ÷ withdrawal rate
Real return = (1 + return − fees) ÷ (1 + inflation) − 1
Coast FIRE number = FIRE number ÷ (1 + real return)years to retirement

Example: spending $40,000 a year at a 4% withdrawal rate gives a $1,000,000 FIRE number. With 7% returns and 2.5% inflation (4.39% real), a 32-year-old retiring at 60 has 28 years of growth ahead, so their Coast FIRE number is $300,277.

Knowing the number is step one. The Coast FIRE calculator shows the month you'll reach it at your current saving rate, and your odds across 1,000 simulated markets.

More FIRE calculators

Coast FIRE calculatorThe month you can stop saving, with odds of success.Barista FIRE calculatorWhen part-time work plus your savings can cover your spending.
FIRE number calculatorHow much you need to retire for good. Coming soon.
Lean and Fat FIREPlan a frugal or a generous retirement. Coming soon.

Questions

What is a Coast FIRE number?

The amount you need invested today so that, without adding anything more, it grows to your full FIRE number by your retirement age. Once you have it, you only need to earn enough to cover today's spending.

How do you calculate your Coast FIRE number?

Divide your FIRE number by (1 + real return) raised to the number of years until retirement. Your FIRE number is your yearly spending divided by your withdrawal rate, and the real return is your expected return after inflation and fees.

What is a good Coast FIRE number at 30?

It depends on your spending and retirement age. Spending $40,000 a year and retiring at 60 with 7% returns and 2.5% inflation, you'd need about $276,000 invested at 30. Use the calculator above for your own numbers.

Why does my Coast FIRE number go up every year?

Each year you wait leaves one less year for compound growth, so you need more invested to reach the same goal. That's why the table by age rises.

Is the Coast FIRE number in today's dollars?

Yes. Everything is in today's money because inflation is taken out of the return, so the FIRE number means the same spending power you have now.