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Coast FIRE Calculator: did you already save enough?

Find the moment you've saved “enough” — where compound growth takes over and you can stop saving for retirement. Drag the sliders, watch the number breathe.

What is Coast FIRE?

Coast FIRE means you've saved enough that compound growth will carry your portfolio to full retirement — without saving another penny. You still work to cover living costs, but the pressure to save for retirement is gone. Think of it like a snowball rolling downhill: once it's big enough, you let go and gravity does the rest. It's the earliest milestone on the FIRE path — lower than full FIRE, but earlier than Barista.

Read the full explainer →
How to use

Three steps to your number

  1. 1
    Enter your numbers
    Age, savings, monthly expenses, and what you save each month — five fields, no signup.
  2. 2
    See your Coast number
    One big result: your Coast FIRE number and whether you’ve reached it yet.
  3. 3
    Drag The Plan slider
    Find how much to save per month and when you can stop — drag age or monthly amount.

Your numbers

Current age 34yrs
1860
Planned retirement age 65yrs
4575
Current savings $25,000
$0$1M
Monthly expenses $3,300/mo
$500$20k
Monthly contribution $500/mo
$0$10k

Figures in today's purchasing power — future dollar amounts will look higher with inflation, but so will your salary.

Your Coast FIRE number
$303,873
You're 8% there · $278,873 to go

Even saving $500/mo until 65 isn't enough — you'd need at least $1,280/mo to reach Coast by retirement.

Your savings trajectory

Continue saving at your pace Coast line (moving target) After your Coast moment FIRE number
$0$248k$495k$743k$990kFIRE number3439444954596465
The Plan

Drag the math,find your pace.

Save $5,113/month → you can stop saving at 39.
That needs about $101K take-home pay — $39.6K to live on + $61.4K to invest.
Target age to stop saving39yrs
3465
Monthly contribution$/mo
$0$7.7K
Quick jumps
Cutting annual expenses by $400 lowers your line by $3.1K. Try Lean FIRE →
Figures in today’s purchasing power — future dollar amounts will be higher with inflation, but so will your salary.

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Try next
Barista FIRE Calculator →FIRE Number Calculator →4% Rule Calculator →
Contact us

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FAQ

The math, explained.

What exactly is the Coast FIRE number? +
It’s the amount you need today so that, even if you never save another dollar, your investments will grow into your full FIRE number by your target retirement age. Below that, you still need to save. At or above it, you can “coast” — live on your income and let compounding finish the job.
Why 7% returns and not the 10% I see elsewhere? +
The S&P 500 has averaged ~10% annually over the past century including dividends. We use 7% nominal to discount for conservatism — fees, taxes, and the gap between index returns and what real investors actually capture. Read our full methodology piece for the breakdown.
Should I include my home equity in “current savings”? +
Generally no — Coast FIRE math assumes liquid, invested assets earning the assumed return. Your primary residence doesn’t generate the compound growth the formula relies on.
What does “monthly expenses” mean here? +
Your normal living costs — rent/mortgage, food, insurance, transportation, utilities. Enter the monthly total; we multiply by 12 internally. Use today’s dollars (what things cost now), not what you expect them to cost at retirement.
Is this financial advice? +
No. It’s an educational tool based on transparent assumptions. Your real returns will vary. For decisions specific to your situation, speak with a licensed financial advisor.

How this number is calculated

Coast FIRE number = (Annual expenses ÷ withdrawal rate) ÷ (1 + real return)^{years to retirement}. Real return = (1 + nominal) / (1 + inflation) − 1 ≈ 3.9% at 7% nominal and 3% inflation. Monthly contribution calculations use monthly compounding. The Coast line is a moving target — it rises each year as you have less time for compound growth to work.

why we use 7% average returns, the 4% rule explained, the 25× rule breakdown.

This tool is for educational purposes only and is not financial advice. Estimates are based on the assumptions shown (e.g., 7% nominal returns, 3% inflation, 4% withdrawal rate). Actual investment returns vary. Consider speaking with a licensed financial advisor.