Coast FIRE is the moment your invested savings are large enough to grow into a full retirement nest egg — without adding another dollar. Find your number below.
Coast FIRE is a milestone within the Financial Independence, Retire Early (FIRE) movement. You hit Coast FIRE the moment you have enough money invested that — assuming reasonable market returns — your portfolio will grow to support a traditional retirement without you contributing another cent. You still need to work to cover your current living expenses, but you no longer have to save for retirement.
Coast FIRE Number = (Annual Expenses ÷ Safe Withdrawal Rate) ÷ (1 + Real Return Rate)Years to Retirement
For example, if you need $50,000/year in retirement and assume a 4% withdrawal rate plus 7% real returns, your full FIRE number is $1,250,000. If you're 30 years old and plan to retire at 65, your Coast FIRE number is roughly $117,000 today — because that amount, growing at 7% real returns for 35 years, will reach $1.25M on its own.
Lean FIRE: Full FIRE with a frugal annual budget (under $40K/year typically).
Fat FIRE: Full FIRE with a generous annual budget ($100K+/year).
Barista FIRE: Partial FIRE — your investments cover most expenses, part-time work covers the rest.
Coast FIRE: Your investments will grow into full FIRE on their own; you only need to earn enough to cover current living expenses.
Most Coast FIRE calculators use a 5–7% real return (after inflation), based on the long-term historical performance of the S&P 500 minus inflation. Conservative planners use 5%, optimistic ones use 7%. The default here is 7%, which matches the most common assumption in the FIRE community.
The main risk is that future market returns are lower than historical averages. If real returns come in at 4% instead of 7%, your portfolio won't grow as projected. Many Coast FIRE planners build in a margin of safety by saving 20–30% beyond their calculated number, or by continuing small contributions.
No — Coast FIRE means you no longer need to save, but you still need income to cover current expenses. You haven't accumulated enough yet to live off your portfolio. That's full FIRE.
The classic answer is 4%, based on the Trinity Study. Some FIRE planners use 3.5% to be more conservative, and a few use 4.5% if they're flexible about spending in down market years.
Use real returns (after inflation) when calculating Coast FIRE, because the formula assumes your annual expenses stay constant in today's dollars. Nominal returns would distort the projection.