$1,000 a month for 20 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $363,842 | $123,842 | $201,450 |
| 5% | $405,804 | $165,804 | $224,684 |
| 6% | $453,439 | $213,439 | $251,058 |
| 7% | $507,536 | $267,536 | $281,011 |
| 8% | $568,999 | $328,999 | $315,041 |
| 10% | $718,259 | $478,259 | $397,683 |
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 |
| 16 | $192,000 | $345,262 | $215,156 |
| 17 | $204,000 | $381,811 | $231,002 |
| 18 | $216,000 | $420,918 | $247,245 |
| 19 | $228,000 | $462,763 | $263,907 |
| 20 | $240,000 | $507,536 | $281,011 |
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) |
|---|---|---|---|
| 10 years | $126,036 | $165,511 | $218,794 |
| 20 years | $306,364 | $474,039 | $752,769 |
The middle of the simulation sits below the steady 7% figure of $507,536 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $507,536 would pay in retirement
At a 4% first-year withdrawal, $507,536 pays about $20,301 a year, $1,692 a month, before tax; in today’s dollars that is about $11,240 a year. How long a balance near it lasts at each withdrawal: how long $500,000 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 |
| $1,000 a month for 15 years | $311,105 | $199,686 |
| 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 20 years
$50 a month: $25,377, $100 a month: $50,754, $150 a month: $76,130, $200 a month: $101,507, $250 a month: $126,884, $300 a month: $152,261, $400 a month: $203,015, $500 a month: $253,768, $600 a month: $304,522, $750 a month: $380,652, $1,500 a month: $761,305, $2,000 a month: $1,015,073, $2,500 a month: $1,268,841, $3,000 a month: $1,522,609, $5,000 a month: $2,537,682.
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.