FIRE Calculator

FIRE (Financial Independence, Retire Early) is a movement focused on aggressive saving and investing to retire decades earlier than traditional retirement age. The 4% rule comes from the 1994 Trinity Study, which found that withdrawing 4% of your portfolio annually (inflation-adjusted) had a ~96% success rate over 30 years. Your FIRE number = Annual Expenses / 0.04 = 25x your annual expenses.

Lean FIRE targets a frugal lifestyle, typically spending under $40,000/year. Regular FIRE targets maintaining your current lifestyle in full retirement. Fat FIRE aims for a luxurious retirement with $100,000+ annual spending. Coast FIRE means you have enough invested that it will grow to your FIRE number without further contributions. Barista FIRE means partially retiring with part-time work covering some expenses.

Savings rate is the single most powerful variable. A 10% savings rate requires ~43 years to FIRE. A 25% rate: ~32 years. A 50% rate: ~17 years. A 75% rate: ~7 years. Every 10% increase in savings rate cuts years to FIRE dramatically because it both grows your portfolio faster AND reduces the FIRE number.

The original Trinity Study covered 30-year retirements. For early retirees with 40-50 year time horizons, a 3.5% or 3% SWR is safer. Flexible withdrawal strategies (spending less during downturns) and part-time income improve success rates substantially. This calculator lets you set any SWR to model different scenarios.

Coast FIRE is the amount you need invested today so that, without adding another dollar, your portfolio grows to your full FIRE number by traditional retirement age. Once you reach Coast FIRE, you only need to cover current living expenses with income – you no longer need to save for retirement.