Crypto DCA calculator

How do you calculate the average cost of a crypto DCA plan?

Dollar-cost averaging (DCA) means spending a set amount at regular intervals, whatever the price. Each purchase buys coins = (amount - fee) / price, so a low price buys more coins and a high price fewer. Add up the money spent and the coins bought, and the average cost per coin = total spent / total coins.

The default plan spends $100 six times at prices of 60,000, 52,000, 45,000, 50,000, 58,000 and 64,000, with a 0.5% fee on each purchase. That is $600 spent, $3.00 of it in fees, for 0.01104311 coins, an average cost of $54,332.52 a coin. Valued at the last price of 64,000, the coins are worth $706.76, a gain of $106.76 or 17.79% on the money spent.

Every price is one you type in. Enter the prices you actually paid to audit a plan you ran, or a list of prices you want to test to see what a falling or rising stretch would do to the average.

What a DCA plan looks like purchase by purchase

Here is the default plan in full. Each $100 purchase loses $0.50 to the fee, so $99.50 buys coins at that day's price:

The purchase at 45,000 bought a third more coins than the one at 60,000 for the same money, and it pulled the average down sharply. By purchase three the plan was worth $260.23 against $300 put in; by purchase six it was ahead. The first chart under the calculator draws the money put in against that value for your own list.

Why is the DCA average cost lower than the average price?

Because a fixed amount buys more coins when the price is low. The simple average of the six default prices is $54,833.33, but the coins were not bought in equal numbers: more of them came at 45,000 and 50,000. Before fees, the average cost is $54,060.85, which is $772.48 below the simple average.

With equal amounts, the average cost before fees is the harmonic mean of the prices: the number of purchases divided by the sum of 1 / price. The harmonic mean of a set of different positive numbers is always below their simple mean, so with equal amounts and no fees, your average cost always comes in under the average price you saw. Fees then add back a little: the 0.5% fee lifts $54,060.85 to $54,332.52.

On the Different amounts tab the result depends on when you put in more. The default there spends $800, with the biggest purchase, $200, at 45,000, and averages $52,610.98, lower again because more money went in near the bottom.

How do fees affect a DCA plan?

A percentage fee takes the same share of every purchase, so it lifts the average cost by the same proportion whatever the amount. A flat fee works differently: it takes a fixed sum, so it weighs far more on small purchases. $2 on a $20 purchase is 10% of the money; on a $200 purchase it is 1%.

Switch the default plan to a flat $1 a purchase and the fees are $6.00 instead of $3.00, the average cost rises to $54,606.92 and the value at 64,000 falls to $703.21. Split the same money into more, smaller purchases and the flat fee takes a bigger bite each time; the calculator says so when flat fees pass 2% of the money spent.

Fees are entered per purchase. If your platform charges a spread instead, built into the price, enter the price you actually paid and set the fee to zero, so the cost is not counted twice.

DCA or one lump sum: what the arithmetic shows

The last line of the results puts the same total into a single purchase at your first price, with one fee, and values it at the same price as the plan. The answer depends entirely on the path the prices took, and the calculator shows it rather than judging it.

• A dip and a recovery (the default). One $600 buy at 60,000 would hold 0.00995 coins, worth $636.80 at 64,000. The plan holds 0.01104311 coins worth $706.76, because it bought through the dip.
• A steady rise. €250 a month at €40,000, €44,000, €48,000 and €52,000 with a 1% fee averages €46,022.79 a coin, worth €1,129.88 at €52,000. One €1,000 buy at €40,000 would be worth €1,287.00.
• A fall that keeps going. Value the default plan at 40,000 and it is worth $441.72, a loss of $158.28. The lump sum would be worth $398.00. Spreading the purchases lost less, but both lost money.

Spreading purchases changes the average price you pay. It does not decide whether the price ends higher or lower than that average, and no schedule removes the risk of the price falling.

Worked examples in pounds and euros

The arithmetic is the same in any account currency; enter every price in that currency and nothing is converted.

In the pound plan, £200 buys 0.1010625 coins. The four prices average exactly £2,000, yet the plan's cost before fees is £1,959.18, the harmonic mean, and the £2 of fees, 1% of the money, lift it to £1,978.97. In the euro plan, prices only rose, so the average cost of €46,022.79 sits just above the €46,000 simple average once the 1% fee is added.

How to calculate DCA average cost in Excel or Google Sheets

Put the amount of each purchase in column A and the price in column B, one row per purchase, and the fee rate as a decimal in E1. In column C, the coins bought are =A2*(1-$E$1)/B2, filled down. The average cost per coin is then =SUM(A2:A7)/SUM(C2:C7), and the value is =SUM(C2:C7)*price.

You can skip the helper column with =SUM(A2:A7)/SUMPRODUCT(A2:A7*(1-E1)/B2:B7). For the default plan, with 100 in every row of column A and 0.005 in E1, both return 54,332.52. A plain =AVERAGE(B2:B7) returns 54,833.33, which is the average price, not what the coins cost you.

What this calculator leaves out

It holds no live prices and makes no forecast: every price, including the one used to value the coins, is a number you enter. It does not include network fees for moving coins to a wallet, the spread inside a quoted price unless you enter the price you paid, or any rewards earned on coins while held. It treats each purchase as complete and does not model a sale.

Crypto rules differ from country to country, and several tax systems track the cost of each purchase in their own way, which may not match this simple average. For the tax on a gain when you sell, see the capital gains tax calculator.

Common DCA mistakes

• Taking the average of the prices. With equal amounts, your cost is the harmonic mean, below the simple average; with different amounts, it can be anywhere.
• Leaving fees out. They are part of what each coin cost, and flat fees weigh most on small purchases.
• Counting a spread twice. If the price you paid already includes the platform's margin, set the fee to zero.
• Valuing at the wrong price. A plan valued at its last purchase price is not the same as one valued at today's price; enter the price you want.
• Reading a lower average as protection. The average can still sit far above the price you later sell at.

Glossary

Dollar-cost averaging (DCA): spending a set amount at regular intervals regardless of price. Average cost per coin: total money spent, fees included, divided by coins held. Harmonic mean: the count of numbers divided by the sum of their reciprocals; the average cost of equal purchases before fees. Lump sum: putting the whole amount in at once. Flat fee: a fixed charge per purchase. Spread: the gap between the buying and selling price, sometimes used in place of a fee.

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