Tax-Loss Harvesting & Capital Loss Carryback Calculator

The calculator above calculates your tax savings from harvesting capital losses, offsets current-year capital gains, and generates an optimized allocation schedule for carrying back net capital losses to the 3 preceding tax years using CRA Form T1A.

In Canadian taxable (non-registered) investment accounts, managing capital losses strategically can substantially lower your tax bill or trigger direct tax refunds from prior years.

The Hierarchy of Capital Loss Deductions in Canada

Under Section 111 of the Income Tax Act, net capital losses must follow a strict statutory order of application:

1. Step 1 — Current Year Offset (Schedule 3): Realized capital losses must first be applied against realized capital gains in the current tax year.
2. Step 2 — 3-Year Carryback (Form T1A): Any remaining net capital loss can be carried back up to 3 prior taxation years ($T-1$, $T-2$, and $T-3$). The CRA applies the loss against prior reported taxable capital gains (Line 12700) and issues a tax refund.
3. Step 3 — Indefinite Carryforward (Line 25300): Any remaining losses after the 3-year carryback can be carried forward indefinitely to offset taxable capital gains in any future tax year.

1
2
3
4
5
6
7

flowchart TD
    A[Realized Capital Loss] --> B{Current Year Gains?}
    B -- Yes --> C[Offset Current Year Schedule 3 Gains]
    B -- No / Excess --> D{Gains in Prior 3 Years?}
    C --> D
    D -- Yes --> E[File Form T1A for Prior Year Tax Refund]
    D -- No / Excess --> F[Carry Forward Indefinitely to Future Years]

How Form T1A (Request for Loss Carryback) Works

If you realize a net capital loss in the current tax year and paid capital gains tax in any of the prior 3 years, you can request a tax refund by filing Form T1A (Request for Loss Carryback) alongside your annual T1 return:

• Year T-1 (Immediate Prior Year): Typically prioritized first to recover the most recent taxes paid.
• Year T-2 (Two Years Prior): Secondary allocation.
• Year T-3 (Three Years Prior): Final eligible carryback year before the 3-year lookback window closes.

Worked Example: $12,000 Loss with Current Gains and Prior Carryback

Consider an investor in a 43.5% marginal tax bracket who harvests a $$12,000.00\text{ CAD}$ capital loss:

• Current Year Realized Gain: $$4,000.00\text{ CAD}$ gross ($$2,000\text{ CAD}$ taxable).
• Year T-1 Taxable Gain Reported: $$3,000.00\text{ CAD}$.
• Year T-2 Taxable Gain Reported: $$2,000.00\text{ CAD}$.
• Year T-3 Taxable Gain Reported: $$1,000.00\text{ CAD}$.

The investor completely eliminates their current tax liability and receives a $$1,740.00\text{ CAD}$ direct refund via Form T1A.

Avoiding the Superficial Loss Rule When Harvesting Losses

When executing a tax-loss harvest, you must avoid the 30-day superficial loss rule. If you or an affiliated person (such as your spouse or your TFSA/RRSP) reacquire an identical property within 30 days before or after the settlement date, your loss will be denied.

Prudent Replacement Strategies:

• Switch to a Materially Different Index / Asset Class: For example, selling a Canadian equity ETF (TSX Composite) and buying a global or U.S. index fund.
• Wait 31 Days: Keep funds in cash or a money market fund until Day +31 after settlement before repurchasing the original security.
• Avoid Identical Property Claims: CRA considers funds from different providers that track the exact same index to generally be identical properties. Choose replacement assets with distinct underlying index methodologies.

Scope note: This calculator models individual loss carryback allocations and tax savings. For continuous portfolio-wide tax loss harvesting monitoring, multi-broker pooling, and superficial loss detection, use myCostBase.