$200 a month for 20 years at returns from 4% to 10%
| Return | Balance | Of which growth | In today’s dollars |
|---|---|---|---|
| 4% | $72,768 | $24,768 | $40,290 |
| 5% | $81,161 | $33,161 | $44,937 |
| 6% | $90,688 | $42,688 | $50,212 |
| 7% | $101,507 | $53,507 | $56,202 |
| 8% | $113,800 | $65,800 | $63,008 |
| 10% | $143,652 | $95,652 | $79,537 |
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 |
| 4 | $9,600 | $10,994 | $9,768 |
| 5 | $12,000 | $14,239 | $12,283 |
| 6 | $14,400 | $17,712 | $14,833 |
| 7 | $16,800 | $21,428 | $17,423 |
| 8 | $19,200 | $25,404 | $20,054 |
| 9 | $21,600 | $29,658 | $22,731 |
| 10 | $24,000 | $34,210 | $25,456 |
| 11 | $26,400 | $39,081 | $28,233 |
| 12 | $28,800 | $44,293 | $31,066 |
| 13 | $31,200 | $49,869 | $33,959 |
| 14 | $33,600 | $55,836 | $36,914 |
| 15 | $36,000 | $62,221 | $39,937 |
| 16 | $38,400 | $69,052 | $43,031 |
| 17 | $40,800 | $76,362 | $46,200 |
| 18 | $43,200 | $84,184 | $49,449 |
| 19 | $45,600 | $92,553 | $52,781 |
| 20 | $48,000 | $101,507 | $56,202 |
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) |
|---|---|---|---|
| 10 years | $25,207 | $33,102 | $43,759 |
| 20 years | $61,273 | $94,808 | $150,554 |
The middle of the simulation sits below the steady 7% figure of $101,507 because ups and downs cost compounding: a 20% loss needs a 25% gain to get back.
What $101,507 would pay in retirement
At a 4% first-year withdrawal, $101,507 pays about $4,060 a year, $338 a month, before tax; in today’s dollars that is about $2,248 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.
$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 |
| 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 |
| $200 a month for 40 years | $494,308 | $151,534 |
Other amounts for 20 years
$50 a month: $25,377, $100 a month: $50,754, $150 a month: $76,130, $250 a month: $126,884, $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.