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    Superficial loss calculator for crypto

    Short answer

    A superficial loss happens when you sell crypto at a loss and you, or an affiliated person, acquire the same coin within 30 days before or after and still hold it 30 days after the sale. The loss is denied in proportion to the units rebought, and added to their cost base instead.

    Runs in your browser · Formulas shown below · General information, not tax advice

    The sale and the 61-day window

    Use the ACB tracker if you're unsure.
    By you or an affiliated person.
    Loss denied now
    $1,206.00

    Of the $2,010.00 loss, $804.00 can be claimed now. The denied $1,206.00 is generally added to the ACB of the 60 substituted units, so it can be recognised when those are sold.

    Loss before the rule
    −$2,010.00
    Units that count (smallest of three)
    60.0000
    Denied share
    60.0%
    Sale dayDay −30Day +30: still own them?bought 0bought 60

    Estimates from your inputs, calculated in your browser; nothing is sent anywhere unless you choose to email results below. Scenario values are illustrative, not quotes or forecasts; past prices do not predict future ones. General information, not tax advice; CRA guidance on DeFi is limited and evolving. Formulas checked 2026-11-02.

    Worked example

    Sell 5 ETH at a loss, buy 3 back, still hold 2 on day 30
    The rule counts the smallest of three numbers: units sold, units bought in the 61-day window, and units still held at the end of it.
    Sell 5 ETH at a loss, buy 3 back, still hold 2 on day 30: inputs, steps and result
    Sold5 ETH for $10,000, $20 fee
    Cost base of the 5 ETH$15,000
    Bought back within 30 days after3 ETH
    Still held 30 days after the sale2 ETH
    Loss before the rule−$5,020.00
    Units that count2 of 5min(5, 3, 2)
    Denied share40%
    Loss denied now$2,008.00$3,012.00 claimable now; the denied part is added to the cost of the 2 ETH still held

    Selling the third rebought coin before day 30 would have cut the denied share; holding all 3 would have raised it to 60%. The denied amount isn't lost: it comes back when the replacement coins are sold.

    Open this example in the calculator →Computed 2026-11-02.

    Mitey the yeti sits on a stone studying a plain gold token through a magnifying glass, a small stack of tokens beside him
    Mitey checks the date on each coin bought back: inside the 61-day window, the loss waits.

    Selling crypto at a loss and buying the same asset back within 30 days can turn part or all of that loss into a superficial loss. It isn't lost forever: it's generally added to the cost base of the units you bought back. This calculator shows how much is denied now.

    How to use it

    1. Enter the units sold, the proceeds and the ACB of those units (from the ACB tracker).
    2. Enter units bought in the 30 days before and the 30 days after the sale, including purchases by affiliated persons.
    3. Enter how many units are still held at the end of day 30 after the sale.
    4. Read the denied amount and the loss you can claim now.

    The two conditions

    CRA's capital-losses page describes a superficial loss as a loss on a disposition where both of these are true: you, or a person affiliated with you, buy or have a right to buy the same or identical property during the period that starts 30 calendar days before the sale and ends 30 calendar days after it; and you or that affiliated person still own (or have a right to buy) the property 30 calendar days after the sale.

    Affiliated persons include your spouse or common-law partner and a corporation controlled by you or your spouse. The legal definition is in section 54 of the Income Tax Act, and paragraph 53(1)(f) is what adds the denied loss to the cost base of the substituted property.

    Quick reading of the rule (illustrative)
    SituationSuperficial loss?
    Sell at a loss, buy back on day 12, still hold on day 30Yes, for the units bought back
    Sell at a loss, buy back on day 31No: outside the window
    Buy more on day −20, sell older units at a loss, hold the new unitsYes: purchases before the sale count too
    Spouse buys the same asset on day 5 and holds itYes: affiliated person
    Sell at a loss, buy back on day 10, sell again on day 25Generally no: not held at the end of the window

    Partial superficial losses

    When fewer units are bought back than were sold, only part of the loss is denied. The common way to compute it, used in this calculator, takes the smallest of three numbers: units sold, units acquired in the 61-day window, and units held at the end of the window. That share of the loss is denied; the rest can be claimed.

    In the default example (illustrative), 100 units with an ACB of $6,000 are sold for $4,000 less $10 in costs, a loss of $2,010. Sixty units are bought in the 30 days after and still held, so 60% of the loss, $1,206, is denied and the remaining $804 can be claimed. The $1,206 is added to the ACB of those 60 units.

    Is a different token “identical”?The rule applies to the same or identical property. CRA's crypto pages don't say whether two different tokens tracking the same asset, or a wrapped version of a token, are identical. Treat that as an open question for professional advice.

    Why the window catches people with DCA or bots

    Automatic purchases keep running after you sell. If you have a recurring buy and you sell at a loss, any automatic purchase within 30 days before or after the sale counts. The same is true of reward income arriving in the window if it is the same asset. The ACB tracker checks all your rows against the window automatically.

    What this calculator does not cover

    It does not see accounts you don't enter, such as a spouse's or a corporation's. It does not cover the listed exceptions on CRA's page (for example a disposition on becoming or ceasing to be a resident, or on death). It also assumes the loss is a capital loss; if your activity is a business, different rules apply to the loss.

    What this means for you

    If you want a loss to count this year, don't rebuy the same coin for 30 days, and check that no automatic purchase or reward lands in the window. Rewards in the same coin can count as acquisitions.

    A denied loss isn't gone: it raises the cost of the replacement coins, so it reduces the gain (or adds to the loss) when you sell them. The ACB calculator applies the rule across all your records automatically.

    Definitions

    61-day window
    The 30 days before the sale, the day of the sale and the 30 days after it.
    Affiliated person
    Includes your spouse or common-law partner and corporations you or they control. Their purchases count too.
    Substituted property
    The units bought in the window; the denied loss is added to their cost.

    Questions people ask

    Does the superficial-loss rule apply to crypto?

    CRA's crypto pages don't mention it specifically, but the rule applies to capital property generally, including identical crypto-assets held as capital property.

    Is the loss gone forever?

    Usually not. CRA says you can usually add the superficial loss to the ACB of the substituted property, which reduces a future gain or increases a future loss when you sell it.

    Does buying before the sale count?

    Yes. The window starts 30 calendar days before the sale and ends 30 calendar days after it.

    What about my spouse buying the same asset?

    Purchases by affiliated persons, which include your spouse or common-law partner, count toward the rule.

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    Sources and dates

    1. CRA — Capital losses and deductions (superficial loss)Date modified 2026-02-05; checked 2026-10-30
    2. Income Tax Act, s. 54 — definition of “superficial loss”Consolidation current to 2026-09-30; checked 2026-10-30
    3. Income Tax Act, s. 53(1)(f) — adjustments to cost baseConsolidation current to 2026-09-30; checked 2026-10-30
    4. CRA — Reporting income from crypto-asset transactionsDate modified 2025-12-02; checked 2026-10-30