FIRE Calculator

Your FIRE number is the amount of savings you need so that your annual expenses can be covered by investment returns without drawing down the principal. It is calculated as annual expenses ÷ safe withdrawal rate. For example, $60,000 expenses at a 4% withdrawal rate means a FIRE number of $1,500,000. The 4% rule comes from the Trinity Study and is a common default.

The calculator projects your portfolio year by year: each year you add (income − expenses) in savings and apply your expected real return (after inflation). When your balance reaches your FIRE number, you have reached financial independence. The "Years to FIRE" result is how many years that takes. If you do not reach it by your target retirement age, the calculator shows "Save more" and you can increase savings rate or extend the target age.

A higher savings rate shortens time to FIRE. Many FIRE followers aim for 50% or more. The calculator shows your current savings rate as (income − expenses) ÷ income. If you are not on track by your target age, try raising your savings rate, reducing expenses, or increasing your target age.

The calculator uses real return so that your FIRE number and projections are in today's purchasing power. Real return = (1 + nominal return) / (1 + inflation) − 1. That way you see when you can afford your current lifestyle in today's dollars, without inflation distorting the timeline.

4% is a common default based on the Trinity Study (roughly sustainable over 30 years). Some use 3–3.5% for longer retirements or more caution. Enter your own rate in the calculator; a lower rate means a higher FIRE number and more years to get there.

Using a 4% withdrawal rate, the target portfolio is $1,500,000 because $60,000 / 0.04 = $1,500,000. With a 3.5% withdrawal rate, the target rises to about $1,714,000. Lower withdrawal rates provide more safety but require more capital.

A 50% savings rate can make a 15-year FIRE timeline possible, especially with consistent investing and 6% to 7% long-run returns. For example, saving $50,000 per year from a $100,000 income can build around $1.25 million in 15 years at 7% assuming no starting balance. Required time changes significantly with market returns and spending needs.

Lean FIRE typically targets lower annual spending, often around $30,000 to $50,000 for a household, while Fat FIRE targets higher spending such as $100,000 or more. At 4%, those imply portfolios of about $750,000 to $1,250,000 for Lean FIRE and $2,500,000+ for Fat FIRE. The right target depends on your expected lifestyle and location costs.

Inflation directly increases the spending number your portfolio must support. If annual spending rises from $60,000 to $75,000, the 4% FIRE target increases from $1,500,000 to $1,875,000. That is a $375,000 increase in required assets from spending inflation alone.

Barista FIRE: you have enough invested to cover the gap between part-time income and expenses. You quit full-time work and supplement with part-time (e.g., barista). Coast FIRE: you have enough today that, without adding more, growth will reach your full FIRE number by retirement age. You keep working but stop saving. Barista needs less capital; Coast needs more upfront.

The 4% rule can underperform with bad sequence of returns (market crash early in retirement), higher inflation than historical, longer than 30-year retirement, or lower future returns. Many retirees use 3–3.5% for extra safety, especially if retiring before 50.

Depends on your spending and withdrawal rate. At $60,000/year spending and 4% withdrawal, you need $1.5M. At 50% savings rate from $100K income, you save $50K/year; at 7% return, that builds ~$1.25M in 15 years from $0. Use the calculator with your numbers.

No. FinCalc (fincalcapp.com) is a separate free FIRE calculator. Firecalc (firecalc.com) is a retirement simulation tool with Monte Carlo and historical scenarios. FinCalc focuses on FIRE number, years to retirement, and savings rate—simpler and faster. Both are free; use whichever fits your needs.