DCA Backtest Calculator

Dollar-cost averaging means investing a fixed amount at regular intervals. This backtest asks what that plan would have produced over a past period; it does not forecast the next one. Choose a stock, ETF or cryptocurrency, a contribution amount, a date range and a monthly, weekly or every-two-weeks schedule.

Purchase dates and fractional units

The schedule starts on your selected start date. Weekly purchases advance by seven calendar days and every-two-weeks purchases by fourteen; monthly purchases advance by a calendar month, so month-end dates can shift. Each purchase uses the first available daily closing price on or after its scheduled date, within the end date. A weekend or missing price can therefore move the purchase to a later date.

Units bought equal the contribution divided by that date’s price. Fractional shares or coins are allowed with no rounding to whole units. For example, a $200 contribution at a $100 price buys two units; at $80 it buys 2.5. These are illustrative numbers, not historical results. The final value is accumulated units multiplied by the last available price on or before the end date.

Reading the return figures

• Total invested: contribution amount multiplied by the number of completed purchases, not an estimate based on years.
• Gain or loss: final value minus total invested. The percentage divides that difference by total invested; it is not an annual return.
• Average cost basis: total invested divided by accumulated units, rather than the simple average of purchase prices.
• DCA money-weighted IRR: an annualized estimate using each purchase date as a cash outflow and the ending value as a cash inflow. It reflects when money entered the plan.
• Lump-sum CAGR: the annualized growth rate of investing the full contribution total at the first purchase price. Its funding assumption differs from DCA, so it is not a like-for-like return metric.

The IRR is a numerical estimate, with a search range of −99% to +500% per year. Extreme results can reach those bounds, and short periods can produce misleading annualized percentages. Read the ending value, contribution total and dates alongside it.

With reinvestment on, stocks and ETFs use dividend-adjusted history where available. Adjusted prices represent a reinvestment model, not actual broker execution prices. Shares accumulated and cost basis in that mode are model units, not a reconstruction of your account’s share ledger.

“Dividends contributed” is the difference between the final adjusted-series result and the price-only result for the same plan. It includes the modeled compounding effect; it is not a cash-dividend total or a payment-by-payment tax record. Without adjusted history, the asset uses price-only data.

The lump-sum comparison invests the DCA plan’s full contribution total on its first purchase date. No interest is credited to cash awaiting future DCA purchases. The SPY comparison uses the same plan settings and dividend toggle, but each asset uses its own available prices. If their histories cover different dates, actual purchases and invested totals can differ: check coverage before declaring a winner.