Trail notes
- Adjusted cost base (ACB) is usually what you paid plus acquisition costs; for crypto, CRA calls it usually the weighted average cost.
- For identical properties, the per-unit ACB is recalculated on every purchase and does not change when you sell.
- CRA’s worked example ends at $20.63 per unit after four steps.
- Crypto-for-crypto trades need Canadian-dollar values at the time of the trade, for both the token you give up and the one you receive.
What adjusted cost base means
Your adjusted cost base (ACB) is what the tax system treats as the cost of your property. When you dispose of crypto-assets, your gain or loss is roughly your proceeds minus the ACB of the units you disposed of, minus any costs of selling.
CRA’s page on crypto-asset transactions (modified 2025-12-02) describes ACB as usually the cost of the property plus expenses to acquire it. CRA’s 2024-10-22 tax tip for crypto-asset users calls ACB “usually the weighted average cost of a crypto-asset.” That weighted average is the average-cost method this page explains.
ACB is pooled across every unit of the same asset you hold, not tracked wallet by wallet or lot by lot. Two units of the same token in two different wallets share one average cost.
The average-cost rule for identical properties
When you own several identical properties, such as many units of the same crypto-asset, the per-unit ACB is the average cost: the total cost of the identical properties you hold divided by the number you hold. The rule comes from section 47 of the Income Tax Act (consolidated to 2026-09-30) and is explained on CRA’s page “Special rules and other transactions” (modified 2026-02-05).
Two features make it work:
- You recalculate on every purchase. Each new acquisition adds its cost to the pool and its units to the count, giving a new average.
- Dispositions do not change the per-unit ACB. When you sell, the units leave the pool at the current average. The average for the units you keep stays the same.
As of 2026-10-30, CRA’s identical-properties page (modified 2026-02-05) says the ACB per unit is recalculated on each purchase and that dispositions of identical properties do not affect the ACB. Section 47 of the Income Tax Act is consolidated to 2026-09-30.
CRA’s worked example, step by step
CRA illustrates the rule with shares. The arithmetic is the same for identical units of a crypto-asset.
| Step | Units held | Total ACB | ACB per unit |
|---|---|---|---|
| Buy 100 for $1,500 | 100 | $1,500 | $15.00 |
| Buy 150 for $3,000 | 250 | $4,500 | $18.00 |
| Sell 200 | 50 | $900 | $18.00 |
| Buy 350 for $7,350 | 400 | $8,250 | $20.63 |
The most common mistake is in step 3. People reduce the per-unit cost when they sell, or recalculate it using the sale price. Neither is right. A sale removes units at the existing average, and the average for what remains is unchanged.
Turning ACB into a gain or loss
CRA’s example does not give a sale price for step 3, so here is a hypothetical one to show the next step.
If the result is a loss, check the superficial loss rule before you count on it, especially if you bought the same asset within 30 days before or after the sale. If your activity looks like trading as a business, see capital vs business income, since the full gain would then be included.
Fees and crypto-for-crypto valuation
Costs of acquiring a crypto-asset, such as a platform’s purchase commission, are generally added to its ACB. Costs of selling generally reduce your gain, as in the example above. CRA has not addressed how network or gas fees paid in DeFi should be handled, so record them carefully and discuss them with a tax professional.
A crypto-for-crypto trade is a disposition of the token you give up and an acquisition of the token you receive. Both sides must be expressed in Canadian dollars at the time of the trade. CRA’s records page asks you to keep the Canadian-dollar value at the time of each transaction. Note which price source you used, and use the same kind of source each time. If the value of what you gave up and what you received differ, ask a tax professional which to use.
Moving units between your own wallets is not a purchase. If your tracking tool imports the incoming side as a new buy, your average cost and unit count will both be wrong. Match each outgoing transfer to its incoming side.
How to check your numbers
- Gather every acquisition and disposition for each asset since you first bought it, across all wallets and platforms.
- Sort by date and time, and remove internal transfers.
- Add acquisition fees to cost, and keep selling fees separate.
- Recalculate the average after each purchase; carry it unchanged through each sale.
- Compare the units your calculation says you hold with your actual balances at year end.
The ACB calculator on this site walks through these steps. Our sibling site also has an ACB calculator for quick checks. If your history includes rewards, airdrops or DeFi actions with unclear cost, a tax professional can help you decide how to enter them.
Your checklist
Questions people ask
How is adjusted cost base calculated for crypto in Canada?
For identical crypto-assets, ACB per unit is the average cost: total cost of the units you hold divided by the number held, recalculated on each purchase. CRA calls ACB usually the weighted average cost for crypto-assets.
Does selling crypto change my ACB per unit?
No. CRA says dispositions of identical properties do not affect the ACB. The units you sell leave at the current average, and the per-unit ACB of the units you keep stays the same.
Are trading fees part of ACB?
Costs of acquiring a crypto-asset are generally added to its ACB, and selling costs generally reduce the gain. CRA has not addressed DeFi gas fees specifically, so record them and confirm the treatment with a tax professional.
Can I use first-in, first-out for crypto in Canada?
For identical properties, the Income Tax Act’s average-cost rule applies, and CRA’s guidance describes ACB as usually the weighted average cost. Ask a tax professional if your situation seems to call for something different.
Sources and dates
- Special rules and other transactions — identical properties — Canada Revenue Agencyin force
Page date 2026-02-05 · checked 2026-10-30. Average-cost ACB for identical properties, recalculated on each purchase; dispositions don't change per-unit ACB (worked example ends at $20.63). - Income Tax Act, s. 47 (identical properties) — Justice Laws Websitein force
Page date 2026-09-30 · checked 2026-10-30. Statutory average-cost rule for identical properties. - Reporting your capital gains as a crypto-asset user (tax tip) — Canada Revenue Agencyin force
Page date 2024-10-22 · checked 2026-10-30. ACB is usually the weighted average cost; half of a capital gain is reported as income. - Reporting income from crypto-asset transactions — Canada Revenue Agencyin force
Page date 2025-12-02 · checked 2026-10-30. Business income vs capital gains is case by case; lists business indicators; crypto-to-crypto trades are dispositions; half of a capital gain is taxable. - Keeping books and records of crypto-assets for tax filing — Canada Revenue Agencyin force
Page date 2025-11-10 · checked 2026-10-30. What to record per transaction, wallet addresses, yearly balances; export platform history; keep records at least six years.
Education only. Nothing on this page is financial, investment, tax or legal advice, or a recommendation to buy, sell, stake, lend or borrow any crypto-asset. Crypto-assets can lose some or all of their value and are not covered by CDIC. Canadian rules change: check the dated sources above and talk to a qualified professional about your situation. Full disclaimer.