Crypto average buy price calculator with fees

Combine purchases of the same asset

Add one row per purchase, with the number of coins, price per coin and percentage buy fee. Keep every row in the same quote currency. A fee of 0.1 means 0.1%. You can add or remove rows, up to 100 purchases.

All fees are paid separately in the quote currency and do not reduce the quantity received. This model covers purchases only: no sales, transfers, airdrops, staking rewards, tax adjustments or leverage are included.

Why a weighted average matters

Buying 1 coin at 100 and 3 coins at 200 gives a purchase value of 700 across 4 coins. Before fees, the weighted average is 175; simply averaging 100 and 200 would incorrectly give 150.

For each row i, let Qᵢ be quantity, Pᵢ be price and fᵢ be the fee percentage divided by 100.

• Row purchase value = Qᵢ × Pᵢ; row fee = Qᵢ × Pᵢ × fᵢ.
• Total quantity = sum of all Qᵢ.
• Total invested = sum of all purchase values and buy fees.
• Weighted average buy price including fees = total invested ÷ total quantity.

Worked example with different fees

This example uses fictional prices in generic quote-currency units. Buy 1 coin at 100 with a 1% fee, then 3 coins at 200 with a 2% fee. Purchase values total 700; buy fees total 1 + 12 = 13. You receive 4 coins and invest 713 in total.

The weighted average cost including fees is 713 ÷ 4 = 178.25 per coin. Selling at that price would only recover the purchase cost before any sell fee; use the profit calculator to include sale fees.

Interpreting your results

Total investment and average cost describe the purchases you enter. They do not establish taxable cost basis, predict future value or account for coins already sold. A transaction ledger is needed if your holdings have changed in other ways.

Quantities and prices must be greater than zero. Fee rates must be at least zero and below 100%. Use ordinary decimal numbers, up to 12 decimal places, without grouping separators or exponent notation; each input may be at most 1,000,000,000,000,000. Results are rounded to at most 18 decimal places after exact fraction arithmetic. Very small nonzero results are marked with < or >.

Exchange fees depend on the venue, order and account. The example values are not current exchange rates. Check your actual order records; the source below explains one exchange's fee model.

Sources

• Coinbase Exchange: trading fees and fee tiers