Stock Long-term Dollar-cost Averaging Investing Returns Calculator
This calculator uses a dollar-cost averaging model to compute investing returns for different investment dollar amounts and different dollar-cost averaging periods for a specified stock.
- Stock Symbol: The calculator accepts any stock, exchange-traded fund (ETF) and mutual fund listed on a major U.S. stock exchange and supported by Alpha Vantage. Some stocks traded on non-U.S. exchanges are also supported. Indexes are not supported.
- Initial Investment ($): buys shares one time on the first date of the monthly closing prices for the stock. Initial Investment must be greater than 0.
- Recurring Monthly Investment ($): buys shares of the stock for dates of monthly closing prices.
- Annual Change in Recurring Monthly Investment ($): is the change in the dollar value of the recurring investment (can be positive, zero or negative). The change is applied to the twelve monthly closing prices that make up each dollar-cost averaging period.
- Investing Period Length (# years): is the total number of years the initial investment and the recurring investments occur. For a given stock the Investing Period Length (# years): determines how many dollar-cost aveagring periods will be computed. For example, an Investing Period Length (# years): of 10 for AAPL (first price is December 1999) made in 2023 would give 14 different dollar-cost averaging periods. In 2024 there would be 15 periods. Note: The Alpha Vantage stock price database begins with December 1999 for stocks trading at that time. Some stocks will have fewer prices because they came public later than 1999.
How the Calculator Works
Here is a simple example that uses the default settings in the input form to help you understand what the calculator does. Suppose you invest $1,000 in the first month of the first year. In the second month through the last month of the first investing period you invest $100. For the second year you invest $110 for each of the twelve months. After that the monthly amount invested increases each year by $10. So for the last year you invest $290 each month.
For a 10 year investing length the calculator sets the first dollar-cost averaging period from 12/1999 through 11/2009. The first monthly closing price for AAPL is 12/1999. It then computes the returns for that period use the dollar-cost averaging model. Next the calculator sets a second dollar-cost averaging period from 12/2000 through 11/2010. Again it calculates the returns for this period. The calculator continues this process for all possible 10-year periods from 12/1999 through the year before the current year. The calculator computes returns for whole years (12 months). For a 10-year investment period there are 14 dollar-cost averaging periods given the current year is 2023.
The valuations end with the last full year of 12 recurring monthly investments.
If you want want a fixed amount invested each month for all years, set Annual Change in Recurring Monthly Investment to 0 on the input form. If you want want to decrease the amount invested each year, set the Annual Change in Recurring Monthly Investment to a negative number on the input form.
Interpreting the Results
The calculator displays its returns for each dollar-cost averaging period in four bar charts:
- Final Dollar Values Chart
- Dollar Gains and Losses Chart
- Percent Gains and Losses Chart
- Average Annual Percent Returns Chart - (Percent Gains and Losses / Investing Length in years)
The calculator displays a table of final dollar values with links to dollar-cost average charts.
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