Coast FIRE Calculator
Coast FIRE is the point where you could stop saving and still reach your FIRE number by a chosen age, because compounding does the rest. You still cover living costs from work until then. The withdrawal rate and the real return are assumptions you can see and change.
Nothing you type is sent anywhere. Your figures stay in this browser tab.
Your coasting point
Assumptions. Withdrawal rate 4%. Expected return 5% real, after inflation, not nominal. No new savings are added. Spending stays in today's dollars, and the portfolio compounds until the target age.
Spending is what you want available at the target age, in today's dollars. Leave invested assets blank to see only the Coast FIRE number, or enter 0 if you have not invested yet.
Coast FIRE number
Coast FIRE number = FIRE number ÷ (1 + real return) ^ years
The FIRE number is annual spending divided by your withdrawal rate. Years are the target age minus your current age. Dividing by compounding at the real return answers a smaller question than the full FIRE number: what has to be invested today if you never add another dollar. Same math as the FIRE calculator, which links here and back.
Whether you are already coasting
You are coasting when invested assets are at least the Coast FIRE number. The gap is that number minus what you have invested. A negative gap means you are past it. The projected portfolio is today's balance grown at the real return with no new contributions. Compare it with the FIRE number.
Withdrawal rate
The withdrawal rate sets the FIRE number the coast is aiming at. It starts at 4% and you can change it. A lower rate raises both the FIRE number and the Coast FIRE number. The result repeats the rate you used.
Real return, not nominal
The growth rate is real, after inflation, not nominal. Spending is in today's dollars, so the portfolio has to be measured the same way. A nominal return would make the Coast FIRE number look too small. 5% real is a common planning assumption. It is not a forecast, and the field is yours to change.
Coasting is not retiring
Coast FIRE does not pay your bills between now and the target age. Work, or some other income, still covers spending. What stops is the need to invest new money for the portfolio to reach the FIRE number on time. If you want the path that includes ongoing savings, use the FIRE calculator's savings-rate mode.
What this does not do
The projection is a smooth real return, not a market path. It ignores fees, taxes, a pension, and a crash near the target age. Read it as the portfolio that works if the return you typed actually arrives. Change the return and see how far the Coast FIRE number moves.
Frequently Asked Questions
Coast FIRE is the invested amount that can grow to your FIRE number by a target age with no further contributions. You are coasting when what you have invested is already at least that amount. You still pay for life from work until the target age. Only the new saving becomes optional.
The ones in the fields, shown again in the assumptions line and under the result. The withdrawal rate starts at 4%. The expected return starts at 5% and is a real return, after inflation. Neither number is locked. The Coast FIRE number is your FIRE number (spending divided by the withdrawal rate) discounted by that real return over the years between the two ages.
Real, not nominal. Inflation is taken out, and spending stays in today's dollars. Entering a nominal return, such as a long-run stock average that still includes inflation, makes coasting look easier than it is. The page states this next to the inputs.
Enter what you have invested. If it is at least the Coast FIRE number, you are coasting, and the result shows how far above you are. If it is short, the result shows the gap. Leave the field blank and you still get the Coast FIRE number, without a yes or no.
The FIRE number is the portfolio that pays your spending at the withdrawal rate. The Coast FIRE number is the smaller amount which, grown at your real return, becomes that FIRE number at the target age. The FIRE calculator's FIRE number mode is the same first step, linked from this page. Its savings-rate mode is the version that keeps adding money each year.
Yes. The calculator runs entirely in your browser and this page performs no lookups. Nothing about your figures leaves the tab. Entries are kept only in this browser (localStorage) so the page remembers them, and Reset wipes them.