Coast FIRE calculator

How much you need invested today so that, without adding another dollar, your portfolio grows into your full retirement number.

Coast FIRE at age 49

Keep investing $1,000 a month for 19 years, 4 months, then stop. Growth alone covers the rest.

Coast FIRE number today: $263,555
FIRE number at 65: $1,000,000
Still to invest: $163,555

What would change your result

Invest $1,650 a month and you reach Coast FIRE by age 40.
Retiring at 68 instead of 65 lowers your Coast FIRE number to $235,088.
Plan to spend $5,000 less a year in retirement and your Coast FIRE number drops by $32,944.

What-ifs worked out from your own numbers. Not personal financial advice.

Your portfolio
Coast FIRE target

Using a 3.88% real return. All amounts in today's dollars.

Year-by-year table

Age	Portfolio	Invested so far	Coast target
30	$100,000	$0	$263,555
31	$116,096	$12,000	$273,790
32	$132,816	$24,000	$284,422
33	$150,186	$36,000	$295,468
34	$168,231	$48,000	$306,942
35	$186,976	$60,000	$318,862
36	$206,450	$72,000	$331,245
37	$226,679	$84,000	$344,109
38	$247,694	$96,000	$357,473
39	$269,526	$108,000	$371,355
40	$292,205	$120,000	$385,777
41	$315,765	$132,000	$400,758
42	$340,240	$144,000	$416,322
43	$365,665	$156,000	$432,490
44	$392,078	$168,000	$449,285
45	$419,516	$180,000	$466,733
46	$448,020	$192,000	$484,859
47	$477,631	$204,000	$503,689
48	$508,392	$216,000	$523,249
49	$540,347	$228,000	$543,570
50	$565,454	$232,000	$564,679
51	$587,414	$232,000	$586,608
52	$610,226	$232,000	$609,389
53	$633,924	$232,000	$633,055
54	$658,542	$232,000	$657,640
55	$684,117	$232,000	$683,179
56	$710,685	$232,000	$709,710
57	$738,284	$232,000	$737,272
58	$766,955	$232,000	$765,904
59	$796,740	$232,000	$795,647
60	$827,681	$232,000	$826,546
61	$859,824	$232,000	$858,645
62	$893,215	$232,000	$891,991
63	$927,903	$232,000	$926,631
64	$963,938	$232,000	$962,617
65	$1,001,373	$232,000	$1,000,000

How it's calculated

Your FIRE number is the portfolio that pays for a year of spending at your withdrawal rate: spending ÷ withdrawal rate. At $40,000 a year and 4%, that's $1,000,000.

Your Coast FIRE number is that amount discounted back to today at the real return: FIRE number ÷ (1 + real return)^{years to retirement}. Once you have it invested, compounding does the rest.

With monthly investing, we step through every month and stop at the first one where your balance meets the Coast target for that age. The target rises each month, so a contribution has to outrun compounding, not just add up.

Questions people ask

What is Coast FIRE?

You have invested enough that growth alone will reach your full retirement number by your target age. From then on you only need to earn what you spend today.

How is Coast FIRE different from Barista FIRE?

With Coast FIRE you keep working to cover current expenses and touch nothing. With Barista FIRE you start withdrawing and use part-time income to cover the rest.

Should I use nominal or real returns?

Enter the return you expect before inflation and the inflation you expect. We convert both to a real return so every result is in today's dollars.

What return should I assume?

The US stock market returned roughly 10% a year before inflation over the last century, about 7% after it. Many planners use 5% to 7% nominal for a mixed portfolio to stay conservative.