Tax-Loss Selling Calculator (Canada)
Estimate the tax savings from realizing a capital loss before December 31. Checks the 30-day superficial loss trap under ITA s.40(2)(g)(i).
Your loss calculator
$445 tax savings
At marginal rate 29.6% on $1,500 allowable loss.
| Realized loss | $3,000 |
| Allowable capital loss (50%) | $1,500 |
| Tax savings | $445 |
Capital losses can only be applied against capital gains in the same year, carried back up to 3 years, or carried forward indefinitely.
The superficial loss trap
The most common mistake in tax-loss selling is triggering the superficial loss rules by rebuying the same security too quickly. Under ITA s.40(2)(g)(i), if you or an "affiliated person" acquires the same or identical property within the 61-day window centred on the sale (30 days before + sale day + 30 days after), the loss is denied. Critically, this includes purchases by your spouse, by a corporation you control, and by your own RRSP or TFSA accounts.
Year-end timing
The trade date must be on or before the last business day of December and must settle in the calendar year. With T+2 settlement, North American equities have a practical cutoff around December 27-28 in most years. Sales settling on January 2 of the next year fall into the next tax year.
How losses can be applied
Allowable capital losses can be applied against:
- • Capital gains in the same year (lowering the gains taxable portion)
- • Capital gains in any of the prior three years (carryback via T1A)
- • Capital gains in any future year (indefinite carryforward, no expiry)
Losses cannot reduce employment income, rental income, dividends, or interest — they only offset gains. The calculator above models the marginal-rate savings as if the allowable loss reduced your taxable income; in practice this is only true if you have matching gains.
Related strategies
If you have realized gains earlier in the year, see the 2026 Capital Gains overview for the 50% inclusion rate that determines your tax bill. If your loss is on a Qualified Small Business Corporation share, see the LCGE Calculator — the CNIL balance interacts with the superficial loss rules.