Coast FIRE Calculator
Coast FIRE Calculator
Your Numbers
All figures are in today's dollars. A 7% nominal return with 2.5% inflation is about 4.5% real; 5% is a common planning assumption.
| Age | Balance | Needed to Coast |
|---|---|---|
| 30 | $80,000 | $289,222 |
| 31 | $96,000 | $303,683 |
| 32 | $112,800 | $318,867 |
| 33 | $130,440 | $334,810 |
| 34 | $148,962 | $351,551 |
| 35 | $168,410 | $369,128 |
| 36 | $188,831 | $387,585 |
| 37 | $210,272 | $406,964 |
| 38 | $232,786 | $427,312 |
| 39 | $256,425 | $448,678 |
| 40 | $281,246 | $471,112 |
| 41 | $307,309 | $494,667 |
| 42 | $334,674 | $519,401 |
| 43 | $363,408 | $545,371 |
| 44 | $393,578 | $572,639 |
| 45 | $425,257 | $601,271 |
| 46 | $458,520 | $631,335 |
| 47 | $493,446 | $662,902 |
| 48 | $530,118 | $696,047 |
| 49 | $568,624 | $730,849 |
| 50 | $609,055 | $767,392 |
| 51 | $651,508 | $805,761 |
| 52 | $696,083 | $846,049 |
| 53 | $742,888 | $888,352 |
| 54 | $792,032 | $932,769 |
| 55 | $843,634 | $979,408 |
| 56 | $897,815 | $1,028,378 |
| 57 | $954,706 | $1,079,797 |
| 58 | $1,014,441 | $1,133,787 |
| 59 | $1,077,163 | $1,190,476 |
| 60 | $1,143,022 | $1,250,000 |
Based on your results — what to do next:
Compare with full FIRE
Your full FIRE number is $1,250,000. Coast FIRE needs only $289,222 today — see Lean, Fat and Barista paths side by side.
See the compounding behind it
$80,000 growing at 5% real becomes $345,755 by age 60 with zero new deposits.
Stress-test your withdrawal rate
A 4% rate on $1,250,000 funds $50,000/yr. Check how it holds up across different retirement lengths.
Coast FIRE means you already have enough invested that, with no more contributions, compound growth alone will carry your portfolio to a full retirement number by your target age. This calculator finds your Coast FIRE number — the balance you need today — by dividing your FIRE number by (1 + real return) raised to the years until retirement, and shows the age you will reach it.
How the Coast FIRE Number Is Calculated
Everything is in today's dollars, so inflation is already baked into the real return. First the calculator sizes your full FIRE number, then it discounts that figure back to today.
① FIRE number
FIRE = Annual spending ÷ Withdrawal rate
$50,000 ÷ 4% = $1,250,000
② Coast FIRE number
Coast = FIRE ÷ (1 + r)n
$1,250,000 ÷ 1.0530 = $289,222
③ Savings if you stop today
Future value = Savings × (1 + r)n
$80,000 × 1.0530 = $345,755
| Variable | Meaning | Typical Value |
|---|---|---|
| FIRE | Portfolio needed to retire | 25× annual spending at a 4% rate |
| r | Real (after-inflation) annual return | 4%–6% |
| n | Years until retirement | Retirement age − current age |
| Withdrawal rate | Share of portfolio spent yearly | 3.25%–4% |
Worked Example — age 30, retiring at 60, $50,000 spending, 4% rate, 5% real return
- FIRE number: $1,250,000
- Coast FIRE number today: $289,222
- With $80,000 saved you are $209,222 short — about 28% of the way there
- If you stopped saving now, $80,000 would grow to $345,755 by 60 — 28% of your FIRE number
💡 Pro-Tip
Coast FIRE is a floor, not a finish line. It only covers the retirement-spending number you entered, and it assumes the real return actually shows up. Many people coast with a part-time or lower-stress job that pays current bills, then keep a small contribution going as a margin of safety. Run it at a 4% real return too — if the plan still works, you have cushion.
Coast FIRE Calculator FAQ
What is Coast FIRE?
Coast FIRE means you have already invested enough that compound growth alone will grow your portfolio to a full retirement number by your target age. You only need to earn enough to cover current living expenses; you can stop (or cut back) retirement contributions.
How do you calculate your Coast FIRE number?
Divide your FIRE number (annual spending ÷ withdrawal rate) by (1 + real return) raised to the years until retirement. At $50,000 spending, a 4% rate, 5% real return and 30 years to go, the Coast FIRE number is about $289,222.
What return should I assume?
Use a real (after-inflation) return. Long-run U.S. stock returns have averaged roughly 6%–7% real, but 4%–5% is a more conservative planning figure for a diversified portfolio.
What is the difference between Coast FIRE and Barista FIRE?
Coast FIRE means your investments will reach the target on their own while you cover current expenses with work income. Barista FIRE means you quit full-time work and use part-time income to cover expenses that your portfolio can't yet fund.
Next Step: Related Calculators
FIRE Calculator
Your Financial Independence, Retire Early number — Lean, Fat, and Coast FIRE.
Compound Interest Calculator
See exponential growth from regular contributions and compounding.
Safe Withdrawal Rate Calculator
Test the 4% rule: max sustainable withdrawal, portfolio longevity, and year-by-year balance.