$750 a month for 40 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $870,798 | $510,798 | $266,949 |
| 5% | $1,111,893 | $751,893 | $340,859 |
| 6% | $1,430,758 | $1,070,758 | $438,609 |
| 7% | $1,853,657 | $1,493,657 | $568,251 |
| 8% | $2,415,810 | $2,055,810 | $740,583 |
| 10% | $4,162,761 | $3,802,761 | $1,276,123 |
Year by year at 7%
| Year | Put in so far | Balance | In today’s dollars |
|---|---|---|---|
| 1 | $9,000 | $9,285 | $9,015 |
| 2 | $18,000 | $19,220 | $18,117 |
| 3 | $27,000 | $29,851 | $27,318 |
| 5 | $45,000 | $53,397 | $46,061 |
| 10 | $90,000 | $128,289 | $95,459 |
| 15 | $135,000 | $233,329 | $149,765 |
| 20 | $180,000 | $380,652 | $210,758 |
| 25 | $225,000 | $587,281 | $280,489 |
| 30 | $270,000 | $877,089 | $361,349 |
| 35 | $315,000 | $1,283,560 | $456,156 |
| 40 | $360,000 | $1,853,657 | $568,251 |
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 $750 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) |
|---|---|---|---|
| 20 years | $229,773 | $355,529 | $564,577 |
| 40 years | $816,686 | $1,622,355 | $3,232,455 |
The middle of the simulation sits below the steady 7% figure of $1,853,657 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $1,853,657 would pay in retirement
At a 4% first-year withdrawal, $1,853,657 pays about $74,146 a year, $6,179 a month, before tax; in today’s dollars that is about $22,730 a year. How long a balance near it lasts at each withdrawal: how long $1.75 million lasts. To stop saving early and let growth do the rest, see Coast FIRE numbers by age.
$9,000 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.
$750 a month for other terms
| Years | Balance | In today’s dollars |
|---|---|---|
| $750 a month for 5 years | $53,397 | $46,061 |
| $750 a month for 10 years | $128,289 | $95,459 |
| $750 a month for 15 years | $233,329 | $149,765 |
| $750 a month for 20 years | $380,652 | $210,758 |
| $750 a month for 25 years | $587,281 | $280,489 |
| $750 a month for 30 years | $877,089 | $361,349 |
| $750 a month for 35 years | $1,283,560 | $456,156 |
| 40 years | $1,853,657 | $568,251 |
Other amounts for 40 years
$50 a month: $123,577, $100 a month: $247,154, $150 a month: $370,731, $200 a month: $494,308, $250 a month: $617,886, $300 a month: $741,463, $400 a month: $988,617, $500 a month: $1,235,771, $600 a month: $1,482,925, $1,000 a month: $2,471,542, $1,500 a month: $3,707,313, $2,000 a month: $4,943,084, $2,500 a month: $6,178,855, $3,000 a month: $7,414,626, $5,000 a month: $12,357,710.
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.