Dollar Cost Averaging Calculator
Same dollars each period at a list of prices — total shares, average cost, and ending value. Click any i for detail.
Contributions & prices
Amount per period ($)
i
Amount
Fixed dollars invested each period. |
|
|---|---|
Price per share each period ($)
i
Prices
Comma-separated list of prices. |
|
Number of periods
i
Periods
If the prices list is shorter, the last price repeats. |
How to use this calculator
- Enter dollars invested each period.
- Paste comma-separated prices.
- Set how many periods to buy.
- Read shares, average cost, and value at the last price.
Results explained
Dollar-cost averaging invests a fixed amount on a schedule regardless of price. Shares each period = contribution ÷ price. Average cost is total invested ÷ total shares. This page ignores fees, dividends, and taxes.
Quick reference: DCA
shares_i = contribution / price_i; avg = invested / shares.
| Item | Detail |
|---|---|
| Falling prices | Buy more shares per dollar |
| Rising prices | Fewer shares per dollar |
| Lump sum vs DCA | Different timing risk — not compared here |
| Fees | Not modeled |
Educational only — not investment advice.
How the estimate is built
shares = Σ (C / P_i); invested = C × n; avg = invested / shares; value = shares × P_last.
Example scenario
$500 at 100,90,80,110,95 → ~26.79 shares, avg cost ~$93.30.
FAQ
What if I enter one price?
Every period uses that price (or repeats the last).
Fractional shares?
Yes — this worksheet allows fractional share math.
Include dividends?
No. Reinvested dividends need a different model.
Is DCA always better?
Not necessarily versus lump sum; it mainly reduces timing regret.