Coast FIRE Calculator

Coast FIRE is having enough invested that, without adding another dollar, compound growth will reach your full retirement number by your target age. Once you 'coast,' you only need to earn enough to cover current expenses — you can stop retirement saving, work less, or take a lower-paying job you enjoy.

Start with your full FIRE number (annual expenses ÷ safe withdrawal rate, e.g. 25× at 4%). Then discount it back to today using your expected real return over the years until retirement: coast number = FIRE number ÷ (1 + real return)^years. The more years you have, the smaller the amount you need now.

Because your FIRE number is in today's dollars. Using a real (after-inflation) return — roughly your nominal return minus about 3% — keeps the projection consistent, so you don't overstate how far your current savings will grow in purchasing power.

Coast FIRE means your investments will grow to your goal on their own, so you just cover current costs. Barista FIRE is similar but usually implies a part-time job (often for health benefits) to bridge the gap. Both let you ease off full-time work well before traditional FIRE.