FIRE Calculator

FIRE — Financial Independence, Retire Early — is a movement built on one central insight: if you can accumulate enough invested assets to cover your living expenses indefinitely, you no longer need to work for money. Financial independence doesn't mean you have to stop working; it means work becomes optional.

The FIRE number (how much you need) is derived from your annual expenses divided by a safe withdrawal rate. The 4% rule comes from the Trinity Study (1998), which found that a portfolio of 50–75% stocks and 25–50% bonds historically survived 30-year retirements with a 4% initial withdrawal rate, adjusted for inflation each year. A 3.5% or 3% withdrawal rate is more conservative for longer retirements (40–50 years).

Annual expenses of $40,000 ÷ 4% = $1,000,000 FIRE number. $60,000 ÷ 4% = $1,500,000. $80,000 ÷ 4% = $2,000,000. Higher expenses require proportionally higher portfolios.

The savings rate is the most powerful variable — it determines both how quickly you accumulate the FIRE number and how low your FIRE number is (since living on less means you need less saved). Saving 10% of income: ~46 years to FIRE. 25%: ~32 years. 50%: ~17 years. 75%: ~7 years. The math explains why high earners with 75% savings rates sometimes retire in their 30s.

FIRE variants: Lean FIRE ($25K–$40K/year), Regular FIRE (current spending level), Fat FIRE ($80K+/year), Barista FIRE (small part-time work supplements a smaller portfolio), and Coast FIRE (enough invested that compound growth will reach your FIRE number by traditional retirement age without further contributions).

Taxes are a critical FIRE planning element. Strategic use of Roth conversions, capital gains harvesting, and Health Savings Accounts can dramatically reduce lifetime tax burden for FIRE achievers.