Dollar-cost averaging (DCA) calculator
Buying a fixed amount on a schedule spreads your entry price. This tool shows the average cost you actually end up with.
On this page
- Dollar-cost averaging means investing the same amount at regular intervals, whatever the price.
- A fixed amount buys more units when the price is low, so your average cost sits below the simple average price when there are no fees.
- With the defaults, five $100 buys at prices from $60 to $110 with a 1% fee give an average cost of $85.07.
- DCA does not prevent losses: if today's price is below your average cost, you are down.
Dollar-cost averaging means investing the same amount at regular intervals, whatever the price. This calculator adds up the units each purchase buys after fees. With the defaults — $100 at prices of 100, 80, 60, 90 and 110, with a 1% fee — your average cost is $85.07 per unit.
How do you use the DCA calculator?
Price at each purchase. Type the prices, separated by commas — one per purchase. They can be real past prices you looked up or made-up scenarios. The site does not fetch prices.
Spent per purchase. The fixed amount you invest each time.
Fee per purchase (%). Your platform's percentage fee. A flat fee can be converted: $1 on $100 is 1%.
Price today. The price you want to value the holding at.
You get the average cost per unit including fees, the simple average of the prices, the total spent, the units accumulated, the value at today's price and the unrealised gain or loss.
How is it calculated?
With amount A per purchase, fee f (decimal), prices p1 … pN and today's price pnow:
Units bought at purchase k = A × (1 − f) ÷ pkTotal units U = sum of all purchasesTotal spent = A × NAverage cost = Total spent ÷ USimple average price = (p1 + … + pN) ÷ NValue = U × pnowandUnrealised gain = Value − Total spent
Because each purchase spends the same money, cheap purchases add more units. Mathematically, the average cost before fees is the harmonic mean of the prices, which is never higher than the ordinary average.
Worked example: why is the average cost $85.07 and not $88?
The $60 purchase bought 1.65 units, the $110 purchase only 0.9. That tilt toward cheaper units is what pulls the average cost below the average price.
How does DCA compare with other scenarios?
All rows spend $500 with a 1% fee. Prices are hypothetical.
| Scenario | Value today | Gain / loss |
|---|---|---|
| DCA, prices 100, 80, 60, 90, 110; today 100 (defaults) | $587.75 | $87.75 |
| Same prices in rising order 60 → 110; today 100 | $587.75 | $87.75 |
| Same DCA, but today's price 70 | $411.43 | −$88.57 |
| One $500 purchase at 100; today 100 | $495.00 | −$5.00 |
| One $500 purchase at 60; today 100 | $825.00 | $325.00 |
Three lessons. The order of the prices does not change the result — only which prices you bought at. DCA beat one purchase at $100 but lost badly to one purchase at the low of $60, which nobody can time in advance. And if the price ends below your average cost, DCA still shows a loss.
What does this calculator not tell you?
- Future prices. The prices are yours. Past prices tell you nothing certain about the next ones, and crypto prices can be very volatile.
- Trading frictions beyond the fee. Market orders fill at the market price, which Investor.gov notes may differ from the price you expected, and the SEC points out that the bid-ask spread is a cost on top of commissions.
- Cash waiting to be invested. Money not yet invested could earn interest elsewhere; the tool ignores it.
- Tax records. Each purchase is a separate lot. The IRS FAQ says basis includes acquisition fees and lets you identify specific units when you sell if you keep records. See crypto tax basics.
Questions readers ask
Can dollar-cost averaging still lose money?
Yes. In the table above, the same five purchases show a loss of $88.57 when today's price is 70. DCA only spreads out when you buy.
Is average cost the same as average price?
No. Average price weights each purchase equally; average cost weights by units bought. With a fixed amount, low prices buy more units, so average cost is usually lower — here $85.07 against $88.00.
Does the order of the prices matter?
Not for the final numbers. The same set of prices in any order gives the same units and average cost. Order matters only for what you would have seen along the way.
How do I compare DCA with investing everything at once?
Enter one price and the full amount as a single purchase — for example price 100 and $500 — and compare the two results. The table above shows both outcomes are possible.
Dollar-cost averaging is a rule for when to buy, and the calculator shows exactly what that rule produced for a given price path: units, average cost and value. It does not tell you which way prices will go. Use it to understand your own purchases, not to predict returns.
Sources
- Internal Revenue Service, Frequently asked questions on virtual currency transactions (2026)Primary source
- Investor.gov, US Securities and Exchange Commission, Market order (glossary) (2026)Primary source
- US Securities and Exchange Commission, Investor Bulletin: Foreign Currency Exchange (Forex) Trading for Individual Investors (2011)Primary source
Educational content only — not financial, investment, legal or tax advice. Crypto-assets are high-risk and you could lose all the money you put in. Rules differ by country; check with your national regulator. See our risk disclosure and editorial policy.
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