FIRE and wealth building.
What it actually takes to retire early — or just earlier
North-star rule of thumb
Save 50% → retire in ~17 years
From Mr. Money Mustache's savings-rate chart, assuming a 5% real return and the 4% withdrawal rule. Adjust either number and the timeline shifts dramatically.
The overview
FIRE — Financial Independence, Retire Early — is a math problem more than a lifestyle. The math: at a sustainable withdrawal rate of 4%, you need 25× your annual spending invested to never run out. So if you spend $50K a year, your FIRE number is $1.25M. Above that, work becomes optional.
The savings rate decides the timeline. The Mr. Money Mustache chart that launched a thousand FIRE blogs shows it in one line: save 10% of your income, retirement is 51 years away. Save 50%, it's 17 years away. Save 70%, it's about 9 years. The income matters less than the gap between income and spending — which is why FIRE communities obsess over both sides of the equation.
The cluster pages below cover the variants (Coast FIRE: invest enough early that you don't need to save anymore, just let it compound; Lean FIRE: a smaller FIRE number with a smaller spending floor; Fat FIRE: a bigger number with more lifestyle room), the math (savings-rate-to-years, 25x rule, sequence-of-returns risk), and the lifestyle honesty (the optimization can become a trap of its own).
What we don't do: claim FIRE is the right finish line for everyone. It's a useful framework for thinking about how much is enough. The number you're trying to hit is yours.
Run the math
The calculators that ground this hub. Free, sourced defaults, your inputs never leave your browser.
Learn the basics
Bite-sized lessons with quizzes and XP. Two minutes a day.
Deeper reads in this guide
Each one is a focused, plain-English breakdown. Articles markedComing soonwill publish on the moneyscale.app weekly content rhythm.
What is FIRE, exactly?
The number, the math, and the four variants people actually pursue.
Coast vs Lean vs Fat FIRE
Three flavors, three savings rates, three lifestyles.
Your FIRE number, calculated
Coming soonThe 25x rule explained, with the spending assumptions to stress-test.
Savings rate vs years to retire
Coming soonThe Mr. Money Mustache chart, reproduced and explained.
How much to invest to retire in 10 years
Coming soonWhat it takes — honestly — and whether it's worth it.
'Passive income' streams that actually exist
Coming soonDividends, index funds, real estate, royalties — and the ones that aren't.
Net worth by age (US benchmarks)
Coming soonFederal Reserve median + mean by age bracket, and what to make of the gap.
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Not financial advice
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