Coast FIRE Calculator

Quick Presets:

Where you are now

$
$
What you're investing toward retirement each month, today.

Your target

$
4% is a common starting point, not a guarantee.

Growth assumption

After inflation and fees — this keeps every figure in "today's dollars."
Real Return Note: US total stock market historically delivers ~6.5%–7% real return after inflation.
Calculation Output & Milestones 🎯 On Track
Coast FIRE progress
Age 59.1
that's when you can stop contributing
Coast FIRE number (today)
$217,639
what you'd need invested right now to coast
Full FI number (at retirement)
$1,250,000
covers annual spend at this withdrawal rate
Progress to Coast FIRE today 23.0%
Worked example will appear here based on your numbers.

Portfolio Glide-Path Simulation

Compounding balance vs. required Coast FIRE threshold
Accumulation (Contributing) Coast Growth ($0 Contributions) Coast FIRE Threshold Full FI Target

Find Your Coast Number & Retirement Age

Coast FIRE is the point where your savings, left to grow untouched, reach your retirement number on their own. Once you hit this milestone, you can stop saving aggressively and simply cover your current living costs.

What is Coast FIRE?

Coast FIRE is the moment your retirement savings become self-sufficient. You've put enough away that, left alone to compound, it will grow into a full retirement fund by the age you choose — without another dollar of new contributions. From that point on, you only need to earn enough to cover your current living costs; the retirement account takes care of itself.

It sits between grinding toward financial independence and reaching it outright. You're not retired yet, but the pressure to save aggressively is gone, which is why a lot of people treat it as a milestone to downshift, switch to lower-stress work, or simply stop stressing about their 401(k) balance.

The Coast FIRE formula

This calculator runs three fundamental steps:

Full FI Number = Annual Spending ÷ Withdrawal Rate
Coast Number (today) = Full FI Number ÷ (1 + Real Return) ^ Years to Retirement
Coast Age = the age your balance, growing with contributions, first reaches the Coast Number

The first step sets your real target using the classic 4%-style withdrawal rule. The second discounts that target back to today's dollars, which gives you the number you need right now to coast. The third simulates your balance forward, month by month, to find the earliest point it clears that number — that's your coast age.

What moves the result the most

Monthly contribution

Contributions matter most before you coast — they're what gets you to the coast number sooner, after which compound growth takes over entirely.

Withdrawal rate

A lower, more conservative withdrawal rate raises your full FI target, which raises everything downstream — including your coast number.

Expected return

A higher assumed return shrinks your Coast Number fast, since more of the growth happens without your help — but an overly optimistic rate will overstate how close you really are.

Years of retirement

More years to compound means a smaller number needed today. Pushing your target retirement age out by even a few years can move your coast date up significantly.

Coast FIRE vs. the other FIRE types

"FIRE" covers several different end states — here's how Coast compares to the others people usually ask about.

Comparison of Coast FIRE, Lean FIRE, Fat FIRE, Barista FIRE and traditional FIRE
TypeWhat it meansStill working?
Coast FIRESavings will grow into your full number by retirement age on their own; you just cover current expensesYes, to cover living costs
Barista FIRESimilar to Coast, but you also draw down some savings and often work part-time for benefits like health coverageYes, part-time
Lean FIREFully retired on a minimal, tightly budgeted annual spendNo
Traditional FIREFully retired, withdrawing from savings to cover a standard, comfortable lifestyleNo
Fat FIREFully retired with a large portfolio supporting an above-average, unrestricted lifestyleNo

Frequently asked questions

Answers to common questions about Coast FIRE, assumptions, and withdrawal rules.

What is Coast FIRE? +
Coast FIRE is the point where your current retirement savings are enough, left alone to grow, to reach your full retirement number by your target retirement age without another dollar of contributions. Once you hit it, you can "coast" — covering only your current living expenses rather than saving aggressively.
How is the Coast FIRE number calculated? +
First find your full FI target: annual spending divided by your withdrawal rate. Then discount that target back to today using your expected investment return over the years remaining until retirement. That discounted figure is your Coast FIRE number — the amount you need invested right now.
What's the difference between Coast FIRE and regular FIRE? +
Regular FIRE means you've saved enough to stop working and live entirely off withdrawals today. Coast FIRE means you've saved enough that growth alone will get you there by a chosen retirement age, so you can keep working but stop saving aggressively, often shifting to lower-pressure or part-time work.
What's the difference between Coast FIRE and Barista FIRE? +
Coast FIRE still assumes you cover your own living costs from current income while your investments grow untouched. Barista FIRE adds a layer: you work a lower-stress job partly for its income and partly for benefits like health insurance, while also drawing down some savings before full retirement.
Can I really stop contributing entirely once I hit Coast FIRE? +
You can stop contributing to that specific retirement goal, but most people keep working and earning enough to cover current living expenses and other goals. Coast FIRE removes the pressure to save aggressively, it doesn't mean you stop earning altogether.
Does this calculator account for inflation? +
Yes, indirectly. Entering a real, inflation-adjusted expected return means every figure the calculator shows is already in today's purchasing power, so you don't need to inflate the results separately.
What withdrawal rate should I use? +
4% is the commonly cited starting point from retirement research, but it's a rule of thumb, not a guarantee. A longer retirement horizon, market conditions at the time you retire, and your flexibility on spending can all justify a more conservative rate like 3% to 3.5%.
Does this calculator include Social Security or a pension? +
No. This version calculates Coast FIRE from investment savings alone, which makes the result a conservative estimate. If you expect meaningful Social Security or pension income, your real Coast FIRE number is likely lower than what's shown here.
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