$1,000 a month for 15 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $244,657 | $64,657 | $157,036 |
| 5% | $264,825 | $84,825 | $169,981 |
| 6% | $286,912 | $106,912 | $184,158 |
| 7% | $311,105 | $131,105 | $199,686 |
| 8% | $337,606 | $157,606 | $216,697 |
| 10% | $398,444 | $218,444 | $255,746 |
Year by year at 7%
| Year | Put in so far | Balance | In today’s dollars |
|---|---|---|---|
| 1 | $12,000 | $12,380 | $12,020 |
| 2 | $24,000 | $25,627 | $24,156 |
| 3 | $36,000 | $39,801 | $36,424 |
| 4 | $48,000 | $54,968 | $48,838 |
| 5 | $60,000 | $71,196 | $61,414 |
| 6 | $72,000 | $88,560 | $74,167 |
| 7 | $84,000 | $107,139 | $87,114 |
| 8 | $96,000 | $127,019 | $100,270 |
| 9 | $108,000 | $148,291 | $113,653 |
| 10 | $120,000 | $171,052 | $127,279 |
| 11 | $132,000 | $195,406 | $141,165 |
| 12 | $144,000 | $221,464 | $155,331 |
| 13 | $156,000 | $249,347 | $169,793 |
| 14 | $168,000 | $279,182 | $184,572 |
| 15 | $180,000 | $311,105 | $199,686 |
The range in 1,000 simulated markets
A 7% average does not arrive as 7% every year. In 1,000 simulated sequences of returns averaging 7% with 12% volatility, this is where $1,000 a month ended up: 1 in 10 markets finished below the first figure, half below the middle one, and 1 in 10 above the last.
| After | Weak (1 in 10 lower) | Middle | Strong (1 in 10 higher) |
|---|---|---|---|
| 8 years | $97,332 | $125,035 | $157,696 |
| 15 years | $206,639 | $297,280 | $422,692 |
The middle of the simulation sits below the steady 7% figure of $311,105 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $311,105 would pay in retirement
At a 4% first-year withdrawal, $311,105 pays about $12,444 a year, $1,037 a month, before tax; in today’s dollars that is about $7,987 a year. How long a balance near it lasts at each withdrawal: how long $300,000 lasts. To stop saving early and let growth do the rest, see Coast FIRE numbers by age.
$12,000 a year is more than the 2026 IRA limit of $7,500 but fits in a 401(k), 403(b) or TSP, whose limit is $24,500. See contribution limits, the 401(k) calculator and the Roth IRA calculator.
$1,000 a month for other terms
| Years | Balance | In today’s dollars |
|---|---|---|
| $1,000 a month for 5 years | $71,196 | $61,414 |
| $1,000 a month for 10 years | $171,052 | $127,279 |
| 15 years | $311,105 | $199,686 |
| $1,000 a month for 20 years | $507,536 | $281,011 |
| $1,000 a month for 25 years | $783,042 | $373,985 |
| $1,000 a month for 30 years | $1,169,453 | $481,799 |
| $1,000 a month for 35 years | $1,711,414 | $608,208 |
| $1,000 a month for 40 years | $2,471,542 | $757,668 |
Other amounts for 15 years
$50 a month: $15,555, $100 a month: $31,110, $150 a month: $46,666, $200 a month: $62,221, $250 a month: $77,776, $300 a month: $93,331, $400 a month: $124,442, $500 a month: $155,552, $600 a month: $186,663, $750 a month: $233,329, $1,500 a month: $466,657, $2,000 a month: $622,210, $2,500 a month: $777,762, $3,000 a month: $933,314, $5,000 a month: $1,555,524.
How it is worked out
Monthly amounts are deposited at the end of each month and compounded monthly at the rate that equals the annual return; lump sums compound once a year. The headline return is 7% a year, the Trinity-style average the site’s retirement pages use; stock-heavy portfolios have averaged more over long periods and bond-heavy ones less, which is why every page shows 4% to 10%. Today’s dollars divide by 3% inflation a year. The range comes from 1,000 simulated sequences of yearly returns averaging 7% with 12% volatility, with each year’s deposits added through the year. Fees and taxes are not taken out. More on the methodology page.