INVESTING
Dollar Cost Averaging Calculator
Backtest a fixed monthly investment in a stock, ETF, index, or crypto and compare total deposits with historical portfolio value.
Current value—Calculate to see a history
Total invested—Each month, the same amount
Annualized return—Rate on each deposit from the month it was made
THE HISTORY
What the deposits became.
Enter a symbol and a monthly amount, then calculate.
THE DEPOSIT
What you would have bought.
How the dollar-cost averaging backtest works
- Fetch adjusted historical prices for the selected symbol and lookback period.
- Invest the chosen fixed amount at each monthly observation.
- Add the shares purchased by each deposit and value them at the ending price.
- Compare ending value with total deposits and calculate a money-weighted annualized return.
Worked example
A $500 monthly plan contributes $6,000 in one year. The ending value can be above or below $6,000 because each deposit buys at a different historical price.
Assumptions and boundaries
- The backtest uses available adjusted price observations and fixed monthly deposits.
- Dividends are reflected only to the extent they are included in adjusted source data.
- Trading costs, taxes, spreads, and fund fees are excluded.
Important limitation: Historical performance does not predict future returns. Symbol history, corporate actions, data availability, and the selected start date can materially affect the result.
Sources and review
Methodology and links reviewed . This educational estimate is not financial, tax, legal, investment, or lending advice.
Frequently asked questions
- Does dollar-cost averaging prevent losses?
- No. It spreads purchases across dates but does not protect against a falling investment or guarantee a gain.
- Why can the annualized return differ from the price return?
- Deposits enter at different times, so the calculation accounts for the timing of each cash flow.