$500 a month for 10 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $73,348 | $13,348 | $54,578 |
| 5% | $77,182 | $17,182 | $57,430 |
| 6% | $81,237 | $21,237 | $60,448 |
| 7% | $85,526 | $25,526 | $63,639 |
| 8% | $90,062 | $30,062 | $67,015 |
| 10% | $99,932 | $39,932 | $74,359 |
Year by year at 7%
| Year | Put in so far | Balance | In today’s dollars |
|---|---|---|---|
| 1 | $6,000 | $6,190 | $6,010 |
| 2 | $12,000 | $12,814 | $12,078 |
| 3 | $18,000 | $19,901 | $18,212 |
| 4 | $24,000 | $27,484 | $24,419 |
| 5 | $30,000 | $35,598 | $30,707 |
| 6 | $36,000 | $44,280 | $37,084 |
| 7 | $42,000 | $53,570 | $43,557 |
| 8 | $48,000 | $63,510 | $50,135 |
| 9 | $54,000 | $74,146 | $56,826 |
| 10 | $60,000 | $85,526 | $63,639 |
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 $500 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) |
|---|---|---|---|
| 5 years | $29,040 | $35,075 | $42,700 |
| 10 years | $63,018 | $82,755 | $109,397 |
The middle of the simulation sits below the steady 7% figure of $85,526 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $85,526 would pay in retirement
At a 4% first-year withdrawal, $85,526 pays about $3,421 a year, $285 a month, before tax; in today’s dollars that is about $2,546 a year. How long a balance near it lasts at each withdrawal: how long $100,000 lasts. To stop saving early and let growth do the rest, see Coast FIRE numbers by age.
$6,000 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.
$500 a month for other terms
| Years | Balance | In today’s dollars |
|---|---|---|
| $500 a month for 5 years | $35,598 | $30,707 |
| 10 years | $85,526 | $63,639 |
| $500 a month for 15 years | $155,552 | $99,843 |
| $500 a month for 20 years | $253,768 | $140,505 |
| $500 a month for 25 years | $391,521 | $186,993 |
| $500 a month for 30 years | $584,726 | $240,899 |
| $500 a month for 35 years | $855,707 | $304,104 |
| $500 a month for 40 years | $1,235,771 | $378,834 |
Other amounts for 10 years
$50 a month: $8,553, $100 a month: $17,105, $150 a month: $25,658, $200 a month: $34,210, $250 a month: $42,763, $300 a month: $51,316, $400 a month: $68,421, $600 a month: $102,631, $750 a month: $128,289, $1,000 a month: $171,052, $1,500 a month: $256,578, $2,000 a month: $342,103, $2,500 a month: $427,629, $3,000 a month: $513,155, $5,000 a month: $855,259.
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.