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MoneyMath

FIRE Calculator — Years to Financial Independence

Calculate how many years until you can retire early using the Financial Independence / Retire Early (FIRE) framework. Uses your current savings, annual savings rate, expected real return, and target withdrawal rate.

🟢 Updated April 2026👤 Reviewed by MoneyMath Editorial⚡ Runs in your browser · inputs never leave your device
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Years to FIRE
17.5
Age 49.5 · target $1,375,000.00
FIRE number (25× expenses)$1,375,000.00
Annual contribution$38,500.00
Contribution over working years$674,428.90
Other FIRE variants
Lean FIRE (60% of expenses)$825,000.00
Fat FIRE (200% of expenses)$2,750,000.00
Coast FIRE (coast to 65, no more contributions)$201,006.06

What is FIRE?

Financial Independence / Retire Early — a movement built around saving aggressively (30-70% of income), investing in low-cost index funds, and reaching a portfolio that can sustain your spending indefinitely without further employment income.

The 4% rule (and why it's not really 4% anymore)

Based on the 1998 Trinity Study, a 4% annual withdrawal from a 60/40 portfolio gave a 95%+ chance of lasting 30 years historically. For FIRE retirees who need 40-60 years of portfolio longevity, most planners now use 3.25-3.5%. Bill Bengen (author of the original study) has updated his estimate multiple times; 3.3% is common as a conservative floor.

How to read the FIRE number

Your "FIRE number" = annual expenses ÷ withdrawal rate. At 4% SWR, that's 25× expenses. At 3.5%, it's ~28.5×. At 3%, 33×. Keep your expenses low and this number drops dramatically — $40K/yr lifestyle needs $1M; $80K/yr needs $2M.

FIRE variants

  • Lean FIRE: retire on a smaller portfolio by keeping expenses low (often <$40K/yr). Geo-arbitrage (Thailand, Portugal, low-cost US towns) is common.
  • Fat FIRE: retire with a cushy lifestyle. Usually $2.5M+ for $100K+ in spending.
  • Coast FIRE: save enough by age ~35-40 that compound growth alone gets you to traditional retirement age with no additional contributions. Extremely freeing — you can take lower-paying, more enjoyable work.
  • Barista FIRE: portfolio covers most expenses + you work part-time for healthcare / fun-money.

The savings-rate math

Mr. Money Mustache's table: savings rate alone determines years-to-FIRE (assuming constant income and 5% real return, starting from zero):

  • 10% savings rate → 51 years to FIRE
  • 25% → 32 years
  • 50% → 17 years
  • 65% → 11 years
  • 75% → 7 years

Raising your savings rate from 25% to 50% cuts FIRE time nearly in half — because you're both saving more AND needing less to retire on.

What this calculator does NOT account for

  • Healthcare pre-65 (can be $10-25K/yr on ACA, factor into expenses)
  • Sequence-of-returns risk in early retirement years
  • Social Security at 67+ (usually adds a floor worth $20-45K/yr)
  • Taxes on withdrawals (Roth ≠ Traditional ≠ brokerage)
  • Possible need for paid-off home (reduces required portfolio)

Frequently Asked Questions

Is 4% safe for a 50-year retirement?

Historically yes in most scenarios, but with less margin. Big Ern's research suggests 3.25-3.5% is safer for retirements of 40+ years. If you can be flexible (cut spending in down markets) 4% is probably fine.

Should I include home equity in my FIRE number?

Usually not, unless you plan to downsize / sell it. A primary residence doesn't produce income. Subtract your expected housing expenses in retirement from your annual-expenses input instead.

What if my savings are in pre-tax 401k, not brokerage?

Use a Roth ladder or 72(t) SEPP to access pre-tax funds before 59.5 without penalty. Factor future tax drag — your FIRE number in pre-tax accounts needs to be ~1.2-1.4x a Roth/brokerage-equivalent number.

Can I FIRE with kids?

Yes, but kids add roughly $200-500/mo per child just to raise (food, clothes, activities), plus college if you fund it. Plan for the full cost over the years you'll have them.

How does Social Security factor in?

If you plan to take SS at 67-70, it becomes a floor that reduces your required portfolio. A $2,500/mo benefit is equivalent to ~$750K at 4% SWR — meaning you can retire earlier on a smaller portfolio if you plan a SS bridge.

What about sequence-of-returns risk?

A 30% market crash in year 1 of retirement is catastrophic. Mitigation: 2-year cash buffer, glide-path bond allocation, flexibility to cut spending, part-time work if markets tank. "Cash cushion" + SWR under 3.5% is the standard defense.