$250 a month for 20 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $90,960 | $30,960 | $50,363 |
| 5% | $101,451 | $41,451 | $56,171 |
| 6% | $113,360 | $53,360 | $62,764 |
| 7% | $126,884 | $66,884 | $70,253 |
| 8% | $142,250 | $82,250 | $78,760 |
| 10% | $179,565 | $119,565 | $99,421 |
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 |
| 11 | $33,000 | $48,851 | $35,291 |
| 12 | $36,000 | $55,366 | $38,833 |
| 13 | $39,000 | $62,337 | $42,448 |
| 14 | $42,000 | $69,795 | $46,143 |
| 15 | $45,000 | $77,776 | $49,922 |
| 16 | $48,000 | $86,316 | $53,789 |
| 17 | $51,000 | $95,453 | $57,750 |
| 18 | $54,000 | $105,230 | $61,811 |
| 19 | $57,000 | $115,691 | $65,977 |
| 20 | $60,000 | $126,884 | $70,253 |
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) |
|---|---|---|---|
| 10 years | $31,509 | $41,378 | $54,699 |
| 20 years | $76,591 | $118,510 | $188,192 |
The middle of the simulation sits below the steady 7% figure of $126,884 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $126,884 would pay in retirement
At a 4% first-year withdrawal, $126,884 pays about $5,075 a year, $423 a month, before tax; in today’s dollars that is about $2,810 a year. How long a balance near it lasts at each withdrawal: how long $150,000 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 |
| $250 a month for 10 years | $42,763 | $31,820 |
| $250 a month for 15 years | $77,776 | $49,922 |
| 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 20 years
$50 a month: $25,377, $100 a month: $50,754, $150 a month: $76,130, $200 a month: $101,507, $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, $1,000 a month: $507,536, $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.