Free Coast FIRE calculator
A Coast FIRE calculator tells you how much you'd need invested today so that, even if you never save another dollar, compound growth alone carries you to a full retirement. Hit that number and your retirement is on autopilot — your paycheck only has to cover current expenses. Coastline computes it against a real, tax-aware retirement target rather than a round guess.
Coast FIRE number by age
The younger you are, the less you need today, because compounding has more time to work. Amount required now to coast to a $1,250,000 nest egg by 65, assuming a 5% real (after-inflation) return:
| Age | Years to grow | Coast number | Growth multiple |
|---|---|---|---|
| 25 | 40 yrs | $178,000 | 7.0× |
| 30 | 35 yrs | $227,000 | 5.5× |
| 35 | 30 yrs | $289,000 | 4.3× |
| 40 | 25 yrs | $369,000 | 3.4× |
| 45 | 20 yrs | $471,000 | 2.7× |
| 50 | 15 yrs | $601,000 | 2.1× |
What Coast FIRE does and doesn't mean
Reaching your Coast FIRE number is a genuine milestone: your retirement is essentially funded, and you gain the freedom to take a lower-paying but more fulfilling job, go part-time, or redirect what you were saving toward life now. It does not mean you can stop working — you still need income to cover current living expenses until you actually retire.
The number rests on two assumptions worth pressure-testing: the return you earn between now and retirement (a weak early stretch does outsized damage), and the target nest egg itself, which depends on your future spending and taxes. Coastline lets you set both and watch the coast number respond.
Why Coastline's version is different
Most free calculators hand you a single headline number with the assumptions hidden. Coastline is built the opposite way:
- Real tax math, not a flat rate. It applies federal and state income tax, long-term capital-gains rules, and account-by-account treatment (taxable, traditional, Roth) — in both your working years and retirement.
- The whole journey. It models accumulation (saving and investing) and drawdown (spending it down), so you see how the plan connects end to end, not just one half.
- The math is shown. Every figure has a click-through breakdown of how it was computed — a level of transparency even paid tools rarely expose.
- US and Canada. It natively handles Canadian plans (RRSP, TFSA, CPP, OAS) alongside US accounts, which most calculators ignore.
- Free, no signup. No account, no email, no account-linking. Your inputs run the projection and are then discarded.
The $1,250,000 target here is the tax-aware nest egg a $60,000/yr retirement at 65 needs; a 5% real return is a common moderate assumption. Set your own target and return in the calculator — and check your number against a lower return too.
Common questions
What is a Coast FIRE calculator?
It finds the amount you’d need invested today so that compound growth alone — with no further contributions — reaches your retirement nest egg by your target age. Past that point you only have to earn enough to cover current expenses.
What is my Coast FIRE number?
It depends on your age and target. For a $1,250,000 retirement at 65 and a 5% real return, about $227,000 at age 30, or $369,000 at 40. The younger you are, the less you need today.
What return should I assume?
A real (after-inflation) return around 5% is a common, moderate assumption for a stock-heavy portfolio over a long horizon. Because markets are uncertain, it’s wise to check your number against a lower rate too.
Is the Coast FIRE calculator free?
Yes, completely free with no signup. Coastline computes your coast number against a real, tax-aware retirement target rather than a round guess.