$200 a month for 40 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $232,213 | $136,213 | $71,186 |
| 5% | $296,505 | $200,505 | $90,896 |
| 6% | $381,536 | $285,536 | $116,962 |
| 7% | $494,308 | $398,308 | $151,534 |
| 8% | $644,216 | $548,216 | $197,489 |
| 10% | $1,110,070 | $1,014,070 | $340,299 |
Year by year at 7%
| Year | Put in so far | Balance | In today’s dollars |
|---|---|---|---|
| 1 | $2,400 | $2,476 | $2,404 |
| 2 | $4,800 | $5,125 | $4,831 |
| 3 | $7,200 | $7,960 | $7,285 |
| 5 | $12,000 | $14,239 | $12,283 |
| 10 | $24,000 | $34,210 | $25,456 |
| 15 | $36,000 | $62,221 | $39,937 |
| 20 | $48,000 | $101,507 | $56,202 |
| 25 | $60,000 | $156,608 | $74,797 |
| 30 | $72,000 | $233,891 | $96,360 |
| 35 | $84,000 | $342,283 | $121,642 |
| 40 | $96,000 | $494,308 | $151,534 |
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 $200 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 | $61,273 | $94,808 | $150,554 |
| 40 years | $217,783 | $432,628 | $861,988 |
The middle of the simulation sits below the steady 7% figure of $494,308 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $494,308 would pay in retirement
At a 4% first-year withdrawal, $494,308 pays about $19,772 a year, $1,648 a month, before tax; in today’s dollars that is about $6,061 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.
$2,400 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.
$200 a month for other terms
| Years | Balance | In today’s dollars |
|---|---|---|
| $200 a month for 5 years | $14,239 | $12,283 |
| $200 a month for 10 years | $34,210 | $25,456 |
| $200 a month for 15 years | $62,221 | $39,937 |
| $200 a month for 20 years | $101,507 | $56,202 |
| $200 a month for 25 years | $156,608 | $74,797 |
| $200 a month for 30 years | $233,891 | $96,360 |
| $200 a month for 35 years | $342,283 | $121,642 |
| 40 years | $494,308 | $151,534 |
Other amounts for 40 years
$50 a month: $123,577, $100 a month: $247,154, $150 a month: $370,731, $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, $750 a month: $1,853,657, $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.