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Coast FIRE Calculator - Find Your Coast FIRE Number

Coast FIRE is the point where you can stop saving entirely and let compound growth carry your current investments to full retirement. Enter your numbers to get your Coast FIRE number, whether you have already hit it, and the age you will - everything inflation-adjusted, in today's dollars. Free, no sign-up.

Your numbers

Coast FIRE number = FIRE number ÷ (1 + real return)years to retirement, where the FIRE number is spending ÷ withdrawal rate (25× at the 4% rule). Real return = return minus inflation, so all figures are in today's dollars.

$229,443
more to invest before you hit Coast FIRE today ($329,443 needed now). Keep saving $20,000/yr and you reach Coast FIRE at age 46.
In today's dollars (3.9% real return)
Coast FIRE number (today)$329,443
Full FIRE number$1,250,000
Coast FIRE age46
Still needed today$229,443
Balance at 65 if you stop saving now$379,428
Retirement income that supports$15,177/yr

Your savings vs the Coast FIRE threshold

The dashed line is the amount that would coast to your FIRE number from each age. Where your savings cross it, you can stop saving for retirement.

Reality-check the assumption: a fixed 7% return smooths over crashes and recoveries. Backtest a real portfolio in the free backtester, then stress-test the spending side with the retirement withdrawal calculator - it replays every retirement since 1871. For the full-FIRE math, use the FIRE calculator.

Coast FIRE questions, answered

What is Coast FIRE?

Coast FIRE means you have already saved enough that, with no further contributions, compound growth alone will carry your investments to your full FIRE number by retirement age. Once you reach it you only need to cover your living expenses - every paycheck stops needing a savings target, hence "coasting".

How is the Coast FIRE number calculated?

Coast FIRE number = FIRE number / (1 + real return) ^ (years until retirement). The FIRE number is your annual retirement spending divided by your withdrawal rate (25x spending at the 4% rule). This calculator uses your expected return minus inflation (the real return), so everything stays in today's dollars.

What is the difference between Coast FIRE and FIRE?

FIRE is having enough invested to stop working entirely. Coast FIRE is the earlier milestone: enough invested that you no longer need to SAVE, but you still work to pay current living expenses until retirement age. Because compounding does the rest of the work, the Coast FIRE number can be a small fraction of the full FIRE number when retirement is decades away.

What is Barista FIRE?

Barista FIRE sits between Coast FIRE and full FIRE: your portfolio covers part of your living expenses, and an easier or part-time job (the proverbial barista gig, often chosen for health insurance) covers the rest. Coast FIRE keeps a full income until retirement; Barista FIRE starts drawing on the portfolio early at a reduced rate.

What return and inflation should I assume?

A common baseline is 7% nominal return for a diversified stock-heavy portfolio and 3% inflation, giving roughly a 4% real return. That is deliberately conservative next to the S&P 500's long-run 10%+ nominal average. You can test any assumption above - and then pressure-test the result against real market history with the backtester.

Does Coast FIRE account for inflation?

This calculator works in today's dollars: growth is compounded at your real (after-inflation) return, so the Coast FIRE number and the projected balances are all in current purchasing power. That is why the default return input pairs with an inflation input rather than assuming nominal growth.