Below is a S&P 500 return calculator with dividend reinvestment. It also has inflation data integrated, so it can estimate total investment returns before taxes. It shows the price return of the index along with the estimated effect of reinvested dividends.
S&P 500 calculator: nominal and inflation-adjusted
For last year, see the 2025 S&P 500 return. Also see the 2024 S&P 500 return.
Pick a starting and ending month and the calculator updates in real time. Here's what it shows:
- Total S&P 500 Price Return – the price return of the index over your window, no dividends. Same level on the start and end month? Mark it 0.
- Annualized S&P 500 Price Return – that price return expressed as a return per year.
- Total S&P 500 Return (Dividends Reinvested) – the total return if you had reinvested every dividend into more of the index.
- Annualized S&P 500 Return (Dividends Reinvested) – the dividend-reinvested total return, annualized.
- Inflation Adjusted (CPI)? – whether the scenario is shown in real, CPI-adjusted terms, using Shiller's CPI series with infill from FRED.
Click Show Chart to graph the growth of $10,000: the blue line reinvests dividends, the gray line is price only, so the gap between them is the dividend contribution piling up. Tick Log scale for a logarithmic vertical axis, which helps keep long, multi-decade windows readable.
Methodology of the S&P 500 Return Calculator
Professor Shiller lists his methodology on his site - all values internal to this tool use the values he provided (outside of the most recent month).
How do monthly S&P 500 prices work?
The month's 'Price' isn't the price on a particular day, but an average of closing prices. It answers "what did the average investor who invested randomly during the beginning month and sold randomly during the ending month do?".
Let me say that again in a different way: other than the most recent month, which is tied to one closing price, the month DOES NOT correspond to an individual day. It's a guess at an average investor's price basis (or sale price) if they bought (or sold) "at some point" in the month.
Also, important (since it comes up often in the comments): because it isn't an individual date, that means when you're trying to compute yearly returns, you need to be careful to pick twelve months - so, if you were interested in the annual return of 2013, you would pick Jan-2013 to Jan-2014 or Dec-2012 or Dec-2013 to get roughly 12 months.
If you want exact dates, try our mutual fund return calculator or ETF return calculator.
How do dividend prices work?
To calculate the 'dividend reinvested' price index:
- Take the trailing twelve month dividend yield reported in any month of Shiller's data.
- Divide by 12 to get an approximate count of dividends paid out in a month.
- Calculate how many 'shares' of the S&P 500 index you can buy.
- Run a cumulative count from your start to your chosen end date.
This will, of course, not match the results of an individual investor. It's extremely complicated to go back and calculate exact S&P 500 payout dates for each fund in each brokerage for one specific investor, and figure out what the index was trading at on that date.
Other Calculators and Other Ways to See S&P 500 Historical Return Data
We also present this data from the perspective of average return over various time periods.
- A Treasury Return Calculator using the same data can be found at that link.
- We also have similar calculators based on the Dow Jones Industrial Average and the NASDAQ.
- An ETF Return Calculator, which may better approximate how individual investors performed.
- Finally, try our individual stock dividend reinvestment calculator.
