Dollar-Cost Averaging Calculator
Dollar-cost averaging means investing a fixed amount on a fixed schedule, whatever the price is doing. This calculator models that habit for a single stock or fund: enter a contribution, a schedule, a starting share price and an assumed yearly price change, and it shows the total you invested, the shares you accumulated, your average cost per share, and what the position would be worth at the end. Everything runs in your browser; nothing you type is sent anywhere.
How the DCA Calculator Works
The calculator walks the schedule one purchase at a time. The share price follows a smooth path at your assumed yearly rate, and at each interval your fixed contribution buys however many shares that period's price allows - fewer when the price is up, more when it is down. Summing those purchases gives your share count; dividing the total invested by that count gives your average cost per share. The ending value is simply shares times the final price. If the mechanics of steady contributions are new to you, the dollar-cost averaging guide covers the strategy itself in plain terms.
Average Cost Is the Number DCA Actually Controls
You cannot control what the market does, and dollar-cost averaging does not try. What it controls is your average cost: because a fixed dollar amount automatically buys more shares at low prices and fewer at high ones, your average cost per share always ends up below the average of the prices you bought at. Try a negative yearly change in the calculator and watch the effect - the ending value may fall, but the average cost falls faster than a single lump-sum purchase at the starting price would have. That mechanical tilt, not market prediction, is the entire argument for the strategy, and seeing the numbers side by side makes it far more concrete than any slogan about buying the dip.
Frequently Asked Questions
Your average cost per share is the total amount you have invested divided by the number of shares you own. When you buy on a schedule, each purchase happens at a different price, so your average cost lands somewhere between the highest and lowest prices you paid. Comparing that average to the current share price tells you instantly whether your accumulated position is up or down overall.
Yes. Dollar-cost averaging controls when and how much you invest, not whether the investment itself gains value. If the share price ends lower than your average cost, the position shows a loss no matter how disciplined the schedule was. What the strategy does do is spread your purchases out, so a badly timed lump sum at a peak is replaced by many purchases at many prices.
Because the two numbers measure different things. The current price is what one share trades for today; your average cost reflects every price you have ever paid, weighted by how much you bought at each. In a rising market a steady buyer's average cost sits below the current price, and in a falling market it sits above it - which is exactly why each new purchase during a dip pulls the average down.
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