DCA controls timing, not return
Investing a fixed amount on a schedule buys more units at lower prices and fewer at higher prices. It does not ensure a profit or protect against a long decline. The result depends on the price path used in the model.
Investing
DCA Calculator
Model equal monthly investments along a smooth price-growth path and estimate shares purchased, average cost and ending value.
Modeled ending value
$36,472.33
Total invested
$30,000.00
Units accumulated
249.822
Average cost per unit
$120.09
Ending modeled price
$145.99
Modeled return
21.57%
Result comparison
Modeled ending value: $36,472.33
Total invested: $30,000.00
Average cost per unit: $120.09
Ending modeled price: $145.99
Modeled ending valueEnding modeled price
Modeled monthly DCA schedule
Detailed values use the same assumptions as the summary above.
| Month | Modeled price | Units purchased | Cumulative units | Total invested | Modeled value |
|---|---|---|---|---|---|
| 1 | $100.00 | 5 | 5 | $500.00 | $500.00 |
| 2 | $100.64 | 4.968 | 9.968 | $1,000.00 | $1,003.22 |
| 3 | $101.29 | 4.936 | 14.904 | $1,500.00 | $1,509.67 |
| 4 | $101.94 | 4.905 | 19.809 | $2,000.00 | $2,019.39 |
| 5 | $102.60 | 4.873 | 24.682 | $2,500.00 | $2,532.38 |
| 6 | $103.26 | 4.842 | 29.525 | $3,000.00 | $3,048.67 |
| 7 | $103.92 | 4.811 | 34.336 | $3,500.00 | $3,568.29 |
| 8 | $104.59 | 4.78 | 39.116 | $4,000.00 | $4,091.24 |
| 9 | $105.26 | 4.75 | 43.866 | $4,500.00 | $4,617.57 |
| 10 | $105.94 | 4.72 | 48.586 | $5,000.00 | $5,147.28 |
| 11 | $106.62 | 4.689 | 53.275 | $5,500.00 | $5,680.40 |
| 12 | $107.31 | 4.659 | 57.935 | $6,000.00 | $6,216.94 |
Real prices are volatile, and this scenario does not include dividends, fees, spreads, taxes or missing contributions.
Calculation method
Monthly DCA calculation
The annual price assumption is converted to an equivalent monthly growth rate. Each monthly contribution buys units at that month’s modeled price.
Detailed guide
Dollar-cost averaging as a repeatable schedule
A DCA calculator divides a regular dollar contribution by the modeled asset price each month. Lower prices buy more units and higher prices buy fewer. The accumulated units and total dollars invested determine the average cost per unit.
Because no external price series is used, this page models a smooth annual price-change assumption. It is useful for understanding the mechanics of recurring purchases, not for predicting the path of a particular stock, fund or cryptocurrency.
Monthly DCA calculation
Units purchased each month = contribution ÷ modeled monthly price
The annual price assumption is converted to an equivalent monthly growth rate. Each monthly contribution buys units at that month’s modeled price.
Average cost equals total invested divided by accumulated units. Ending value uses the final modeled price.
Decision guide
Interpret a dollar-cost averaging projection
The Google results are often short tools, but the useful concepts are contribution frequency, changing purchase prices, total units, and the difference between a planned schedule and a market forecast.
Keep the schedule realistic
Match contribution frequency to actual cash flow and include transaction fees when they are material. A schedule that requires selling emergency assets or borrowing is not sustainable. Missed contributions reduce both invested capital and potential growth.
Compare with a lump-sum case carefully
A lump sum has more time in the market but more immediate timing exposure. DCA delays part of the investment. Compare the same total capital, dates, fees, and assumed price path rather than treating either method as universally superior.
DCA scenario checks
- Use feasible contribution dates.
- Include meaningful fees.
- Keep total capital comparable.
- Test a falling-price path.
How to compare scenarios
Save a baseline, then change only one input at a time: amount, rate, term, or recurring payment. Record the supporting outputs as well as the headline result—contributions, interest, total cost, remaining balance, or target date. This isolates the assumption that actually changes the decision instead of hiding it inside several simultaneous edits.
Do not tune every assumption until the calculator produces a preferred answer. Start with a cautious case, follow with a central case, and treat the favorable case as an upside scenario. A calculator result is not a lender quote, market forecast, or tax determination; actual dates, rounding, fees, contract rules, and required payments must be checked in primary documents.
Keep enough precision in the inputs and round only the output used for a decision. If the estimate supports a transaction, loan, tax calculation, or long-term plan, repeat it with figures from the contract or official statement. Any difference helps identify the assumption that still needs verification.
What a smooth model leaves out
Volatility
Actual DCA results depend on the order and depth of price changes. Two paths with the same ending price can produce different average costs.
Income and fees
Dividends, distributions, commissions and bid-ask spreads are not included.
Lump sum comparison
This page does not declare DCA better than investing immediately. That comparison depends on cash availability, returns and risk tolerance.
DCA calculator questions
What is dollar-cost averaging?
It is a schedule of investing a fixed dollar amount at regular intervals regardless of the current price.
Does the calculator use real market prices?
No. It creates a transparent path from the annual price-change assumption you enter.
Why is average cost different from average price?
Average cost is weighted by how many units each fixed contribution buys at each price.
Data sources
These primary sources explain the rules and concepts referenced by this calculator. The calculation itself uses only the assumptions entered above.
Updated: August 1, 2026
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