How Much Do I Need?

Calculate your FIRE number and explore different retirement strategies — from Lean to Fat FIRE.

This is where every FIRE journey starts: figuring out your number. Whether you're aiming for Lean FIRE on a minimalist budget or Fat FIRE with no compromises, these calculators turn your income, expenses, and goals into a concrete target. All estimates use the 4% rule methodology backed by the Trinity Study.

Who this category is for:

If you're just starting your FIRE journey, begin with the FIRE Number Calculator. Already have a number? Explore Coast FIRE to find your coast number, or Barista FIRE if you want a semi-retirement path.

All 26 Calculators in This Category

Frequently Asked Questions About How Much Do I Need?

What is a FIRE number?

Your FIRE number = annual expenses × 25. This is based on the 4% withdrawal rule: you can safely withdraw 4% of your portfolio each year without running out of money over a 30-year retirement (Trinity Study, Bengen 1994).

Which FIRE strategy is right for me?

Start with the standard FIRE Number Calculator. Lean FIRE targets a minimalist budget ($20K-30K/year). Fat FIRE maintains a high-spending lifestyle ($100K+/year). Coast FIRE lets you stop saving early while your portfolio grows. Barista FIRE combines part-time work with portfolio withdrawals.

Do these calculators account for my country?

Yes. We have country-specific FIRE number calculators for 20 countries with local currency, cost of living, and tax considerations. Find your country in the list below.

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