Coast FIRE Calculator

When can you stop saving for retirement? Inflation-honest math, live results, every chart point tappable.

Your Coast FIRE number today
Full retirement target
Progress to coasting
Coast age on your path
Stop-today value at retirement
The race to coasting

The coast number rises every year you wait — later starts leave compounding less runway. Your personal checkpoints, live from the calculator inputs:

Coast targets, age by age
AgeCoast number thenYour projected balanceStatus on current path

A green pill means your projected path is at or above the coast requirement at that age; an amber pill shows the remaining gap. Edit any input on the Calculator tab and this table follows instantly.

Coasting versus the classic grind: what saving your entire retirement number by your target age would demand every month.

The full-FIRE grind, for contrast

For contrast: the full-FIRE grind

What it would take to reach your entire retirement number by your target age — no coasting, saving the whole way.

Monthly needed for full FIRE
Your planned monthly
Total future deposits (full FIRE)
Deposits until you coast

How the math works

Why this calculator disagrees with sloppier ones: everything here runs in today's dollars. The real return is (1 + return) ÷ (1 + inflation) − 1 by exact division — not the subtraction shortcut, which flatters the result more every year it compounds — and your coast number is the retirement target (spending ÷ withdrawal rate) discounted at that real rate. Contributions are constant purchasing power, credited at month-end.

Coast FIRE splits retirement saving into a sprint and a glide: reach the critical mass first, then let time finish the job while your paycheck only funds the present. It buys career flexibility — not a hammock — and it's only as robust as the assumptions you feed it, so stress-test them in the guide below.

More tools