$250 a month for 10 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $36,674 | $6,674 | $27,289 |
| 5% | $38,591 | $8,591 | $28,715 |
| 6% | $40,618 | $10,618 | $30,224 |
| 7% | $42,763 | $12,763 | $31,820 |
| 8% | $45,031 | $15,031 | $33,507 |
| 10% | $49,966 | $19,966 | $37,179 |
Year by year at 7%
| Year | Put in so far | Balance | In today’s dollars |
|---|---|---|---|
| 1 | $3,000 | $3,095 | $3,005 |
| 2 | $6,000 | $6,407 | $6,039 |
| 3 | $9,000 | $9,950 | $9,106 |
| 4 | $12,000 | $13,742 | $12,210 |
| 5 | $15,000 | $17,799 | $15,354 |
| 6 | $18,000 | $22,140 | $18,542 |
| 7 | $21,000 | $26,785 | $21,779 |
| 8 | $24,000 | $31,755 | $25,068 |
| 9 | $27,000 | $37,073 | $28,413 |
| 10 | $30,000 | $42,763 | $31,820 |
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 $250 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 | $14,520 | $17,537 | $21,350 |
| 10 years | $31,509 | $41,378 | $54,699 |
The middle of the simulation sits below the steady 7% figure of $42,763 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $42,763 would pay in retirement
At a 4% first-year withdrawal, $42,763 pays about $1,711 a year, $143 a month, before tax; in today’s dollars that is about $1,273 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.
$3,000 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.
$250 a month for other terms
| Years | Balance | In today’s dollars |
|---|---|---|
| $250 a month for 5 years | $17,799 | $15,354 |
| 10 years | $42,763 | $31,820 |
| $250 a month for 15 years | $77,776 | $49,922 |
| $250 a month for 20 years | $126,884 | $70,253 |
| $250 a month for 25 years | $195,760 | $93,496 |
| $250 a month for 30 years | $292,363 | $120,450 |
| $250 a month for 35 years | $427,853 | $152,052 |
| $250 a month for 40 years | $617,886 | $189,417 |
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, $300 a month: $51,316, $400 a month: $68,421, $500 a month: $85,526, $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.