Tools
S&P 500 investment calculator
Model a regular investment plan tracking the S&P 500. The calculator uses one fixed, documented historical total-return assumption of 10.0% a year and lets you adjust everything that genuinely depends on you: contributions, time, fund cost, FX charges and inflation. The index itself cannot be bought — a real ETF's result will differ.
How we set the 10.0% return assumption
The calculator uses a fixed 10.0% nominal annual total-return assumption for the S&P 500. This is based on the long-term compounded return of US large-cap equities, including reinvested dividends. It cannot be edited, because it is a published methodology assumption rather than a user input.
In the historical series maintained by Aswath Damodaran at NYU Stern, $100 invested from the beginning of 1928 grew to approximately $1,157,598.95 by the end of 2025. Across 98 annual periods, that corresponds to a compound annual growth rate of approximately 10.018%: ($1,157,598.95 ÷ $100)^(1/98) − 1. We round this to 10.0% to avoid suggesting greater precision than historical data can provide. S&P Dow Jones Indices also reports an annualised total return of approximately 10% since the official launch of the S&P 500 in 1957.
The S&P 500 did not return 10% every year. Some years produced substantial gains and others substantial losses. The figure is a long-term historical reference, not a forecast or a guaranteed return, and past performance does not predict future results.
The S&P 500 was officially launched in its present 500-company form on 4 March 1957. Figures relating to earlier periods are reconstructed or back-tested historical data, not live index history.
Results are shown before personal taxes and before ETF costs unless you enter those costs separately. Your outcome may differ from the index because of ongoing charges, tracking difference, transaction costs, withholding taxes and currency movements. The index itself cannot be bought: investors normally gain exposure through an index-tracking fund or ETF.
Currency note: The historical return assumption is based on S&P 500 total returns in US dollars. This calculator does not predict changes in exchange rates. Your actual return in euros may therefore be higher or lower.
The projection runs month by month. Your annual return assumption is converted to a compounding-consistent monthly rate, contributions are added according to the timing you choose, and the annual fund cost is deducted from the balance each month.
Contributions accumulate as cash and are invested when an order is placed. If you set fewer transactions per year, the money waits in cash between orders and does not earn a return during that time — which is what happens with a real periodic sweep.
Inflation is applied at the end to show the value in today's money. Taxes, withholding on dividends, spreads and any account-level charges are not included. This is an illustration built from your assumptions, not a forecast, and past performance does not predict future results.
"S&P 500" refers to the index; this tool is not affiliated with or endorsed by S&P Dow Jones Indices.
Common questions
- Can I invest in the S&P 500 directly?
- No. An index is a measurement, not a product. You invest through a fund or ETF that tracks it, and your result will differ from the index because of the fund's ongoing cost, tracking differences and any currency effects.
- Why does the calculator ask about FX fees?
- If you invest in euros or pounds into a dollar-denominated fund, a conversion charge can apply to your contributions. It is small per transaction and easy to overlook, but it repeats every month for decades.
- Where does the 10.0% return assumption come from?
- It is the long-term compounded historical total return of the S&P 500, including reinvested dividends: $100 invested from the start of 1928 grew to about $1,157,598.95 by the end of 2025, which is roughly 10.018% a year over 98 periods. We round it to 10.0% and fix it, so the calculator states one transparent assumption instead of inviting a made-up return. It is a historical reference, not a forecast.
- Is currency risk included?
- Only the conversion cost is modelled, not exchange-rate movement. If your home currency strengthens against the dollar, your returns in home-currency terms will be lower than the index suggests, and vice versa.
- Is InvestBeacon affiliated with S&P Dow Jones Indices?
- No. "S&P 500" is used here only to describe the index this calculator illustrates. This tool is not affiliated with, sponsored by or endorsed by S&P Dow Jones Indices.