$600 a month for 25 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $305,309 | $125,309 | $145,817 |
| 5% | $351,441 | $171,441 | $167,850 |
| 6% | $405,773 | $225,773 | $193,800 |
| 7% | $469,825 | $289,825 | $224,391 |
| 8% | $545,395 | $365,395 | $260,483 |
| 10% | $739,995 | $559,995 | $353,426 |
Year by year at 7%
| Year | Put in so far | Balance | In today’s dollars |
|---|---|---|---|
| 1 | $7,200 | $7,428 | $7,212 |
| 2 | $14,400 | $15,376 | $14,494 |
| 3 | $21,600 | $23,881 | $21,854 |
| 5 | $36,000 | $42,718 | $36,849 |
| 10 | $72,000 | $102,631 | $76,367 |
| 15 | $108,000 | $186,663 | $119,812 |
| 20 | $144,000 | $304,522 | $168,606 |
| 25 | $180,000 | $469,825 | $224,391 |
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 $600 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) |
|---|---|---|---|
| 13 years | $103,172 | $144,567 | $202,534 |
| 25 years | $259,478 | $438,192 | $736,295 |
The middle of the simulation sits below the steady 7% figure of $469,825 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $469,825 would pay in retirement
At a 4% first-year withdrawal, $469,825 pays about $18,793 a year, $1,566 a month, before tax; in today’s dollars that is about $8,976 a year. How long a balance near it lasts at each withdrawal: how long $450,000 lasts. To stop saving early and let growth do the rest, see Coast FIRE numbers by age.
$7,200 a year fits in an IRA, whose 2026 limit is $7,500 under 50. See contribution limits, the 401(k) calculator and the Roth IRA calculator.
$600 a month for other terms
| Years | Balance | In today’s dollars |
|---|---|---|
| $600 a month for 5 years | $42,718 | $36,849 |
| $600 a month for 10 years | $102,631 | $76,367 |
| $600 a month for 15 years | $186,663 | $119,812 |
| $600 a month for 20 years | $304,522 | $168,606 |
| 25 years | $469,825 | $224,391 |
| $600 a month for 30 years | $701,672 | $289,079 |
| $600 a month for 35 years | $1,026,848 | $364,925 |
| $600 a month for 40 years | $1,482,925 | $454,601 |
Other amounts for 25 years
$50 a month: $39,152, $100 a month: $78,304, $150 a month: $117,456, $200 a month: $156,608, $250 a month: $195,760, $300 a month: $234,913, $400 a month: $313,217, $500 a month: $391,521, $750 a month: $587,281, $1,000 a month: $783,042, $1,500 a month: $1,174,563, $2,000 a month: $1,566,084, $2,500 a month: $1,957,605, $3,000 a month: $2,349,126, $5,000 a month: $3,915,209.
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.