DCA calculator
Dollar-cost averaging means buying the same dollar amount on a schedule. This calculator shows what that does to your average cost, using prices you enter.
Photo: “Business Working” by Marc Chouinard, CC0 1.0, via Stocksnap (edited: cropped and resized).
With dollar-cost averaging you invest a fixed amount at regular intervals, so you buy more units when the price is low and fewer when it is high [1]. Your average cost is total invested ÷ total units bought. It lowers timing risk; it does not prevent losses.
Key points
- 1Each purchase buys amount ÷ price units, so low prices buy more units and high prices buy fewer.
- 2Average cost per unit = total invested ÷ total units. With equal amounts it is never above the simple average of the prices you paid.
- 3DCA spreads out when you buy. If the price keeps falling, or never recovers, you still lose money.
- 4Every figure on this page is arithmetic on prices you enter, not a forecast.
Average cost per unit
- Purchases counted
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- Units bought
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- Total invested
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- Simple average of prices
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- Value at last price
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- Gain / loss at last price
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Runs entirely in your browser. Nothing you type is sent anywhere. Results are arithmetic, not advice — read the risk disclosure.
What formula does this calculator use?#
Average cost per unit = Total invested ÷ Total units, where units per purchase = Amount ÷ Price on that dateThe calculator divides your fixed amount by each price you list, adds up the units, and divides the total money invested by that total. It then values all units at the last price in your list to show a gain or loss.
The SEC’s investor education site defines dollar-cost averaging as investing equal portions at regular intervals regardless of market ups and downs, and notes that you will buy more of an investment when its price is low and less when it is high [1]. The formula above is exactly that sentence written as arithmetic.
Because a fixed amount buys extra units at low prices, your average cost per unit is pulled toward the low prices. With equal amounts it can never be higher than the plain average of the prices; the two are equal only when every price is the same.
What does the default example show?#
| Purchase | Price | Units bought | Units held so far |
|---|---|---|---|
| 1 | $100 | 1.00 | 1.00 |
| 2 | $80 | 1.25 | 2.25 |
| 3 | $50 | 2.00 | 4.25 |
| 4 | $80 | 1.25 | 5.50 |
| 5 | $100 | 1.00 | 6.50 |
Hypothetical prices chosen to illustrate the arithmetic. They are not real market data.
| Step | Value |
|---|---|
| Total invested = 5 × $100 | $500.00 |
| Total units = 1 + 1.25 + 2 + 1.25 + 1 | 6.500000 |
| Average cost per unit = $500 ÷ 6.5 | $76.92 |
| Simple average of the five prices = $410 ÷ 5 | $82.00 |
| Value at last price = 6.5 × $100 | $650.00 |
| Gain at last price = $650 − $500 | $150.00 (+30.00%) |
The price ended exactly where it started, yet the plan shows a gain, because the $50 purchase bought twice as many units as the $100 ones. That only happened because the price came back. If the price had stayed at $50 for the last two purchases too, the plan would hold 8.25 units worth $412.50 at the end — a loss of $87.50 on $500 invested.
Does DCA beat investing everything at once?#
Not always. The table compares three hypothetical price paths. “Lump sum” means investing the whole amount at the first price instead of spreading it out.
| Price path | Total invested | DCA value at end | Lump-sum value at end |
|---|---|---|---|
| Rising: $50 → $80 → $100 | $300 | $425.00 | $600.00 |
| Falling: $100 → $80 → $50 | $300 | $212.50 | $150.00 |
| Down and back: $100 → $80 → $50 → $80 → $100 | $500 | $650.00 | $500.00 |
In a steadily rising market, buying everything at the start would have ended higher. In a falling market, DCA lost less but still lost money. Nobody knows in advance which path a price will take. The SEC describes DCA as a strategy that can help you manage risk [1]; nothing in the arithmetic makes it a way to earn more.
What does the calculator leave out?#
- Fees. A fixed fee on every small purchase takes a bigger share of each buy; add fees to your amount if you want them counted.
- Taxes, which depend on where you live.
- The chance that an asset never recovers. Regulators warn that you may lose all the money you invest in crypto-assets [2].
- Platform risk: the company holding your coins could fail or halt withdrawals [3].
Frequently asked questions#
What prices should I enter?
To review a plan you already ran, enter the prices you actually paid. To study history, use closing prices from a source you trust. The calculator does not fetch prices for you.
Why is my average cost lower than the average price?
A fixed amount buys more units when the price is low, so low prices carry more weight in your average. That is the arithmetic of DCA, not a sign of profit.
Does DCA protect me from losses?
No. It spreads out your purchase dates. If the price falls and stays down, a DCA plan loses money too.
Does the calculator store what I type?
No. It runs in your browser and sends nothing to us.
The bottom line#
A DCA calculator turns a simple rule — same amount, regular dates — into an average cost you can check. Use it to understand your own purchase history, and remember that the result depends entirely on prices nobody can predict.
Sources#
Grade A = primary source (regulator, protocol specification, client code, original author). Grade B = expert secondary source used for explanation only.
- AU.S. SEC, Investor.gov. Dollar Cost Averaging, 2026.
- AEuropean Supervisory Authorities (EBA, ESMA, EIOPA). EU financial regulators warn consumers on the risks of crypto-assets, 2022.
- AU.S. SEC, Investor.gov. Exercise Caution with Crypto Asset Securities: Investor Alert, 2023.