Coast FIRE is the amount that, left alone, grows to your retirement goal without another dollar added. See your coast number and whether you have hit it.
Coast FIRE is the amount invested today that, left completely alone, grows to your retirement goal without another contribution. This calculator finds your coast number and tells you whether your current savings have already reached it.
First, find your full FIRE number: annual retirement spending divided by a safe withdrawal rate, often 4%. Then discount that back to today at your expected real return over the years until retirement. That present value is your coast number. Reaching it means compounding alone can carry you to retirement, even if you never invest another dollar.
Hitting Coast FIRE does not mean stopping work; it means your retirement is on track without further saving, freeing income for other goals or a lower-stress job. Most people keep contributing for a cushion, since real returns vary and life changes. Use a conservative real return here, and revisit the number as your plans and markets shift.
FIRE is the full amount you need to retire now. Coast FIRE is the smaller amount that will grow into that number by retirement without more contributions.
A real (after-inflation) return keeps the goal in today's dollars, so the coast number reflects purchasing power rather than inflated future figures.
You can, but many people keep saving for a margin of safety, to retire earlier, or to spend more later, since returns are never guaranteed.
See the exact formula and a worked example on our methodology page.