Capital Gains Tax in Canada: How the Math Works
Short Answer: A capital gain is the profit from selling an asset for more than it cost you. Canada taxes only a portion of that profit - the "inclusion rate" - by adding it to your taxable income. This guide explains the inclusion-rate concept, adjusted cost base, and a full worked example.
By Finance Editorial Desk | June 14, 2026
This guide is educational only and is not tax advice. Tax rules change from year to year, and proposals that are widely reported do not always become law. Verify current inclusion rates, thresholds, and exemptions with the Canada Revenue Agency (CRA) or a tax professional before making decisions.
1. What a capital gain is
A capital gain occurs when you sell a capital asset - such as shares, a rental property, or a business - for more than you paid for it. If you sell for less than you paid, the result is a capital loss. Only the profit is ever in question; your original investment is not taxed again when you sell.
A simple example: you buy shares for 14,000. Your capital gain is 4,000 ends up in your taxable income.
2. The inclusion rate: only part of the gain is taxed
Canada does not add the full capital gain to your taxable income. Instead, an "inclusion rate" determines what fraction of the gain is included. For illustration, with a 50% inclusion rate, a 2,000 to your taxable income. That $2,000 is then taxed at your marginal income tax rate, like other income.
The inclusion rate used here is illustrative. Canada's inclusion rate has been the subject of public proposals to change it - including proposals for tiered rates above a threshold - and proposals do not always become law. Because the rate directly changes your tax bill, confirm the current inclusion rate with the CRA or a tax professional before relying on any figure.
3. Adjusted cost base and selling costs
Before any inclusion rate applies, you need the actual gain. The formula is:
- Proceeds of disposition is the selling price.
- Adjusted cost base (ACB) is what the asset cost you: the purchase price plus acquisition costs (legal fees, land transfer tax) plus capital improvements. For a property, a new roof or an addition generally counts; repainting a room does not.
- Outlays are the costs of selling: real estate commission, legal fees on the sale, advertising.
Getting the ACB right matters because every dollar of ACB you can document is a dollar removed from the taxable gain.
4. Worked example: selling a cottage
Suppose an individual sells a family cottage. All figures below are hypothetical and for illustration only.
- Proceeds of disposition (selling price): $850,000
- Original purchase price: $400,000
- Capital improvements added to ACB (new dock, septic system): $50,000
- Selling costs (commission, legal fees): $45,000
Step 1 - Adjusted cost base:
Step 2 - Capital gain:
Step 3 - Apply an illustrative 50% inclusion rate:
The 71,000 - an effective rate of 20% on the full $355,000 gain. Your marginal rate depends on your total income and province; verify current brackets with the CRA.
5. Salary versus capital gain: a conceptual comparison
The table below uses an illustrative 50% inclusion rate to show why a dollar of capital gains is treated more lightly than a dollar of salary. These are concepts, not anyone's actual tax bill.
| $100,000 of salary (illustrative) | $100,000 capital gain (illustrative) | |
|---|---|---|
| Added to taxable income | $100,000 | $50,000 |
| Why | Employment income is fully included | Only the included portion counts |
| Practical meaning | Taxed at your full marginal rate | Roughly half the income is exposed to tax |
This difference is why investors pay close attention to whether a return arrives as interest, dividends, or capital gains - each is included in income differently.
6. How the inclusion rate interacts with your marginal rate
The inclusion rate and your marginal tax rate multiply. With an illustrative 50% inclusion rate, the effective tax on a $100,000 gain is simply half your marginal rate:
| Illustrative marginal rate | Tax on the $50,000 included gain | Effective rate on the $100,000 gain |
|---|---|---|
| 30% | $15,000 | 15% |
| 40% | $20,000 | 20% |
| 50% | $25,000 | 25% |
This is why two people with the same gain can owe very different amounts of tax: the gain is stacked on top of their other income, and the marginal rate on that stack depends on everything else they earned that year.
7. The principal residence exemption
Gains on a property you designate as your principal residence are generally exempt from capital gains tax in Canada. You can only designate one property per family unit as a principal residence for a given year, so if you own both a city home and a cottage, the designation choice matters. The exemption rules have conditions and reporting requirements, and they can change - confirm the current rules with the CRA before relying on them.
8. Capital losses: offsetting gains
If you sell an asset for less than its ACB, you have a capital loss. Capital losses can generally be used to offset capital gains, but not other kinds of income such as salary. Unused losses can generally be carried back up to three years or carried forward indefinitely to apply against gains in other years.
A simple illustration: a 30,000 allowable loss, which can offset $30,000 of taxable capital gains. The carry-back and carry-forward rules, and how losses interact with inclusion-rate changes between years, are technical - verify the current treatment with the CRA or a tax professional.
9. Tracking your cost base over time
For shares bought at different times, the ACB is the weighted average cost of all identical shares you own. For example, buying 100 shares at 20 gives a total cost of 15 per share. Selling 100 shares at 10 per share against the $15 average, not against either purchase price alone.
Brokerage statements usually track this for you, but if you hold the same security across multiple accounts, the averaging applies across all of them. Keep your own records.
10. Timing sales across tax years
Because a capital gain is taxed in the year you realize it, spreading large sales across calendar years can keep each year's gain smaller. Whether that saves tax depends on the inclusion-rate structure and your marginal rate in each year - both of which you must verify as current. The general principle is durable: lumpy, one-time gains can push you into higher brackets, so model the sale year by year before you commit.
11. A brief note on corporations and trusts
Gains earned inside a corporation or trust are taxed under different rules from gains earned personally - the inclusion rate, the timing, and the way after-tax amounts reach the owner all differ. Comparing personal versus corporate ownership of an investment is a technical exercise with real money at stake. Get professional advice rather than relying on general articles.
12. Frequently asked questions
What counts as capital property?
Common examples are shares, bonds, rental real estate, and business assets. Personal-use property (a car, furniture) is generally not taxed on gains, with limited exceptions for high-value items.
Do I pay capital gains tax when I sell my home?
Gains on a designated principal residence are generally exempt, but the exemption has conditions and reporting requirements. Confirm the current rules with the CRA.
What records should I keep for my adjusted cost base?
Purchase confirmations, receipts for capital improvements, and records of selling costs. For shares, keep every buy and sell confirmation so the weighted average can be reconstructed.
Can a capital loss reduce the tax on my salary?
Generally no. Capital losses offset capital gains, not employment or interest income. Unused losses can be carried to other years' gains.
Are gains inside a TFSA or RRSP taxed as capital gains?
No. Investment growth inside these registered accounts is not taxed as capital gains while it stays inside the account. Withdrawals from an RRSP are taxed as income; qualified TFSA withdrawals are generally tax-free. Confirm current account rules with the CRA.
What happens to capital gains when someone dies?
Canada generally treats death as a deemed disposition: assets are considered sold at fair market value immediately before death, which can trigger capital gains in the final return. Estate planning around this rule is technical - get professional advice.
13. Before you sell: a records checklist
- Confirm the current inclusion rate and any thresholds with the CRA - do not rely on remembered figures.
- Reconstruct your ACB: purchase price, acquisition costs, and documented capital improvements.
- Total your outlays: commissions, legal fees, and other selling costs.
- Compute the gain, apply the current inclusion rate, and estimate the tax at your marginal rate.
- Check whether loss carry-forwards from prior years can offset the gain.
- If the asset could qualify for the principal residence exemption, confirm the designation rules first.
Reviewed by the Finance Editorial Desk. Last updated June 14, 2026.