Enough

Alternative to Mr. Money Mustache's fire calculator

The MMM shockingly simple math: how soon you can retire.

Mr. Money Mustache's famous 'Shockingly Simple Math Behind Early Retirement' post reduces the entire problem to one table: your savings rate → your years to FI. Here's what that table says for your numbers.

Assumed return

5.0%

Withdrawal rate

4.0%

Savings rate

65.0%

Peter Adeney, writer of the Mr. Money Mustache blog

What Mr. Money Mustache's Numbers Mean For You

Using Mr. Money Mustache's assumed 4.0% withdrawal and 5.0% return. "Years to FI" assumes a $50,000 starting portfolio and $2,000/month contributions.

Annual SpendingFIRE # (Mr. Money Mustache)FIRE # (4% rule)Years to FI
$40,000$1,000,000$1,000,00020.8y
$70,000$1,750,000$1,750,00029.1y
$120,000$3,000,000$3,000,00038.2y

The Methodology

Peter Adeney (MMM) published 'The Shockingly Simple Math Behind Early Retirement' in 2012. It assumes 5% real return (after inflation) and the Trinity-Study-based 4% safe withdrawal rate. At those assumptions, your savings rate alone determines years to FI: save 10% → 51 years; 25% → 32 years; 50% → 17 years; 65% → 10.5 years; 75% → 7 years. Most of the math isn't investing — it's trimming spending, because higher savings rate compounds in two directions (saving more AND needing less).

Citations

  • “5% real return assumption” — MMM, 'The Shockingly Simple Math Behind Early Retirement', 2012
  • “4% safe withdrawal rate” — MMM blog, Trinity Study references
  • “Savings rate alone determines years to FI” — The Shockingly Simple Math table
  • “Cycling / anti-car / frugality as core practice” — mrmoneymustache.com, passim

Our Honest Take

Where Mr. Money Mustache is right

The core insight — savings rate is the only variable that matters — is right. MMM is also right that most lifestyle upgrades are invisible to the people you're trying to impress and visible to your own FI timeline. His frugality stack (cycling, cooking at home, low-cost hobbies) is a real wealth-creation engine.

Where we differ

MMM's Longmont, Colorado context biases his numbers. A 65% savings rate in Longmont means a different lifestyle than a 65% savings rate in Brooklyn or Silicon Valley. Geographic arbitrage — earning in a high-cost city while spending in a low-cost one, or eventually relocating — can do what MMM-style frugality does, with less lifestyle friction. We compute MMM-style years-to-FI while also showing what happens if you add geo-arbitrage to the stack.

Try the Enough FIRE Calculator

Set your own return and withdrawal rate assumptions. Pick any city in the world to adjust your FIRE number for local cost of living.

Open FIRE CalculatorSafe Withdrawal Rate Tool

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Where You Retire Changes Your Number

Mr. Money Mustache's math assumes a generic US cost of living. The state or country you retire in can move your FIRE number by 30-70%. Start with a tax-friendly state or an international destination:

Florida

No income tax

Texas

No income tax

Portugal

D7 + NHR

Thailand

Territorial

Browse all 50 US states → · International retirement guides →

This page is an independent educational analysis of Mr. Money Mustache's publicly stated retirement methodology. It is not officially endorsed by or affiliated with Mr. Money Mustache or their organization. Retirement planning involves significant uncertainty — consult a qualified fiduciary advisor before acting on any calculation.