How to use the crypto DCA calculator
There are two tools. Average buy price works from purchases you have already made. DCA plan models a schedule of equal purchases.
Average buy price
- Add a row for each purchase of the same coin: the dollars you spent and the price per coin. Your exchange’s order history lists each fill. If one order filled at several prices, enter each fill or the order’s average price.
- Enter the fee in dollars if your exchange charged one. The calculator treats it as part of the amount spent, so it reduces the coins you received.
- Enter the current price to see the value and the profit or loss.
DCA plan
- Enter the amount per purchase, how often you buy and how many purchases to model.
- Enter the fee as a percentage of each purchase. Recurring-buy features on some platforms charge more than ordinary trades, so check the rate.
- Enter a price for each purchase. Paste prices from your history, or type a path you want to test. The example is a made-up Coin A that falls by a third and then recovers. If you list fewer prices than purchases, the last one repeats.
How the average cost is calculated
Average cost = Total spent ÷ Total coins
Average price before fees = (Total spent − Total fees) ÷ Total coinsTotal spent includes the fees. In the DCA plan the fee is a percentage: coins = Amount × (1 − Fee %) ÷ Price.
Profit or loss = Value − Total spent
Rise needed to break even = Average cost ÷ Current price − 1For a fixed amount per purchase and no fees, the average cost equals the harmonic mean of the prices: n ÷ (1/P1 + 1/P2 + … + 1/Pn).
Worked examples
Average buy price. You bought Coin A four times, spending $1,450.00 in total, including $7.25 of fees. That bought 1,463.198622 coins, an average cost of $0.9910 per coin, or $0.9860 before fees. At $1.10 the coins are worth $1,609.52, an unrealized profit of $159.52 (+11.00%).
DCA plan. Making 12 purchases of $100 each in Coin A, one a week, with a 0.5% fee, invests $1,200.00 and buys 1,371.638393 coins. The prices averaged $0.8950, but your average cost before fees was $0.8705, 2.74% lower, because the cheap weeks bought more coins. At the last price of $1.1500 the coins are worth $1,577.38.
If the price in the first example were $0.85 instead, the same coins would be worth $1,243.72, a loss of $206.28, and the price would need to rise 16.59% to get back to your average cost.
What dollar-cost averaging does and does not do
The same $100 weekly plan gives very different results depending on the path of the price:
| Price path over 12 purchases | Average price | Your average cost before fees | Result at the last price |
|---|---|---|---|
| Falls, then recovers (example) | $0.8950 | $0.8705 | $377.38 |
| Falls steadily by two thirds | $0.6700 | $0.6003 | -$523.78 |
| Rises steadily | $0.7750 | $0.7349 | $505.85 |
Three points stand out. First, in every pattern your average cost before fees sits at or below the average price; that is a mathematical property of fixed-dollar buying, not luck. Second, it does not prevent losses: in a steady decline the plan loses money because the price ends below what you paid on average. Third, in a steady rise, buying everything at the start would have bought more coins, so spreading purchases costs you something when prices only go up.
Dollar-cost averaging is best understood as a rule for timing: it removes the decision of when to buy, and it limits the damage of putting everything in at a peak. Whether it beats investing a lump sum depends on the price path, which nobody knows in advance. The Bitcoin investment calculator compares the two on any price history you paste.
Common mistakes with average cost
- Averaging the prices instead of weighting them. The simple average of the four example prices is $1.0000, not your $0.9860 average price. The right figure weights each price by the coins bought there.
- Leaving out fees. Fees raise your cost per coin. On small, frequent purchases they can be a noticeable part of the total.
- Mixing coins or networks. Wrapped or bridged versions of a coin are different assets with their own prices and risks. Keep each one in its own calculation.
- Forgetting transfers out. Coins sent to a wallet with a network fee are fewer than the coins you bought. Use the coins you actually hold when you value the position.
- Treating the break-even price as a target. It tells you where you stop losing money, not where the price is likely to go.
What this calculator does not include
- Sales. It models purchases only. To see the result of selling, use the crypto profit calculator.
- Taxes and tax lots. US tax rules may match sales to specific purchases rather than to the average. The crypto tax calculator covers the tax side.
- Staking or lending rewards, which add coins without a purchase price.
- Real prices. The example prices are fictional. Results depend entirely on the prices you enter, and past prices do not predict future ones.