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Investment and Retirement Calculator
Compound what you save up to the day you retire, then draw it down and see whether it lasts. Every figure below comes with its arithmetic, in today’s dollars or nominal, year by year.
What this calculator assumes
Compounding, stated plainly
The rate you pick is a nominal annual rate. Compounding it more often than once a year makes it worth more than its face value: 8% compounded monthly is an effective 8.30% a year. Contributions land at the end of each period, and money paid in between credit dates sits as cash until the next one rather than earning a slice of a period. Those are the SEC’s conventions on investor.gov, and NerdWallet’s. This engine reproduces four of their published figures to the cent, including the awkward case of monthly deposits under annual compounding.
Where the return presets come from
The S&P 500’s long-run nominal total return with dividends reinvested is about 10% a year, roughly 7% once inflation is taken out. Bonds and Treasuries sit near 5% nominal. A 60/40 mix lands near 8%. Index funds tracking the S&P are the stock line, not a separate asset with its own return. None of these is a forecast, and no year looks like the average.
Nominal against real
A million dollars 35 years out doesn’t buy what a million buys now. The toggle divides every figure by inflation compounded over the same period. Long-run US CPI inflation has averaged near 3% a year; the Federal Reserve targets 2%.
The withdrawal phase
Withdrawals come out before that period’s interest is credited, on the same schedule as the compounding, and step up with inflation every year so the spending power stays flat rather than the dollar figure. Money you’ve already spent can’t be earning a return. The 4% default is the Bengen and Trinity study starting rate, which was derived from a 30-year US stock and bond history. It is a starting point for a conversation, not a guarantee.
What is deliberately not modelled
Taxes, account types, employer matching, IRS contribution limits, catch-up contributions, fund fees, sequence-of-returns risk and Social Security. Each of those moves the answer, and a projection that pretends otherwise is worse than one that says so. Returns are applied as a smooth annual rate; real markets aren’t smooth.
Your plan
$500 monthly is $6,000 a year.
10% compounded monthly is an effective 10.47% a year.
Long-run US CPI is near 3%. The Fed targets 2%.
Your inputs live in the address bar. Bookmark it, text it, come back to it.
At age 65
$1,898,319
$674,631 in today's money after 3% inflation
You put in
$210,000
Growth
+$1,688,319
Years
35
The withdrawal phase
The money lasts past age 92
Starting at age 65 you take $75,933 in the first year, rising with 3% inflation each year after so it keeps buying the same amount. The balance earns 5% nominal while you spend it. At age 92 there's still $1,309,736 left, which is $209,544 in today's money.
First-year withdrawal
$75,933
Same in today’s money
$26,985
Total withdrawn
$3,091,195
Left at 92
$1,309,736
Show the working
How $1,898,319 was arrived at
- The rate. You chose 10% nominal, compounded monthly (12 times a year). That is an effective annual rate of 10.4713%, because (1 + 10%/12)12 minus 1 = 10.4713%.
- When interest lands. Interest is credited 12 times a year at 0.8333% a go, a factor of 1.0083333. You deposit 12 times a year, and money paid in between credit dates sits as cash until the next one. That is the convention investor.gov and NerdWallet both use, which is why this page agrees with them.
- Your deposits. $500 at the end of each month, 420 deposits in all, totalling $210,000. Each one earns interest from the next credit date until you retire, which comes to $1,898,319.
- The total. That is $1,898,319.03. Of that, $210,000 is money you put in and $1,688,319 is growth.
- In today’s money. $1,898,319 ÷ 1.030035 = $674,631. That is what the balance buys in 2026 prices.
- The withdrawal. 4% of $1,898,319 is $75,933 in the first year, taken out as $6,327.73 a month and stepped up 3% every year after.
Year by year
The full schedule
62 rows, age 31 to 92.
| Age | Opening | Paid in | Taken out | Growth | Closing | Today’s $ |
|---|---|---|---|---|---|---|
| 31 | $0 | $6,000 | - | +$283 | $6,283 | $6,100 |
| 32 | $6,283 | $6,000 | - | +$941 | $13,223 | $12,464 |
| 33 | $13,223 | $6,000 | - | +$1,667 | $20,891 | $19,118 |
| 34 | $20,891 | $6,000 | - | +$2,470 | $29,361 | $26,087 |
| 35 | $29,361 | $6,000 | - | +$3,357 | $38,719 | $33,399 |
| 36 | $38,719 | $6,000 | - | +$4,337 | $49,056 | $41,083 |
| 37 | $49,056 | $6,000 | - | +$5,420 | $60,475 | $49,172 |
| 38 | $60,475 | $6,000 | - | +$6,615 | $73,091 | $57,698 |
| 39 | $73,091 | $6,000 | - | +$7,936 | $87,027 | $66,699 |
| 40 | $87,027 | $6,000 | - | +$9,396 | $102,422 | $76,212 |
| 41 | $102,422 | $6,000 | - | +$11,008 | $119,430 | $86,279 |
| 42 | $119,430 | $6,000 | - | +$12,789 | $138,219 | $96,944 |
Timing
What starting sooner is worth
Same contributions, same return, same retirement age. Only the start date moves.
| Start | Age | At 65 | Difference |
|---|---|---|---|
| 5 years earlier | 25 | $3,162,040 | +$1,263,721 |
| 3 years earlier | 27 | $2,580,170 | +$681,851 |
| 1 year earlier | 29 | $2,103,381 | +$205,062 |
| Your plan | 30 | $1,898,319 | - |
| 1 year later | 31 | $1,712,695 | -$185,624 |
| 3 years later | 33 | $1,392,563 | -$505,756 |
| 5 years later | 35 | $1,130,244 | -$768,075 |
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The breakdown, then about one email a year. No sales pitch, unsubscribe any time.Important disclaimers
Not financial advice. This calculator is educational. It isn’t financial, investment, tax or legal advice, and it isn’t a recommendation. Talk to a qualified adviser before you act on it.
A smooth rate is a fiction. Returns are applied at a constant rate. Real markets deliver the average across decades and almost never in any single year, and the order those years arrive in matters enormously once you start withdrawing. Two portfolios with the same average return can end very differently.
Not modelled. Taxes, account type, employer matching, IRS contribution limits, catch-up contributions, fund fees and Social Security. Fees in particular compound against you the same way returns compound for you.
Past returns. The preset rates describe what US markets have done over multi-decade periods. They aren’t forecasts and no one is promising them to you.