Capital Gains Tax in Ontario: What You Need to Know

Capital gains are one of the more misunderstood elements of Canadian taxation. Many Ontario investors know they owe tax when they sell an investment for a profit, but far fewer understand exactly how that tax is calculated, what the inclusion rate means in practice, or the various rules and strategies that can meaningfully affect the tax bill. Getting this right matters — capital gains can represent tens or even hundreds of thousands of dollars for investors with significant portfolios.

What Is a Capital Gain?

A capital gain arises when you sell a capital property — stocks, mutual funds, ETFs, real estate (other than your principal residence), business interests — for more than its adjusted cost base (ACB). The ACB is essentially what you paid for the asset, including purchase costs and any adjustments required under the Income Tax Act.

Capital gain = Proceeds of disposition − Adjusted cost base − Selling costs

If the result is positive, you have a capital gain. If negative, you have a capital loss. Losses can be used to offset gains, as discussed below.

The key principle: capital gains are not taxed until they are realized — meaning you sell or are deemed to have sold the asset. Unrealized gains (paper profits on assets you still hold) are not taxable. This gives investors meaningful control over the timing of their tax liability.

The Inclusion Rate: How Much of Your Gain Is Taxable

Canada does not tax capital gains at 100%. Instead, only a fraction — called the inclusion rate — is added to your income and taxed at your marginal rate.

For individuals, the inclusion rate on capital gains has historically been 50% (one-half). This means that if you realize a $100,000 capital gain, $50,000 is added to your taxable income. The other $50,000 is tax-free.

An important note for 2024 and beyond: The federal government announced an increase in the capital gains inclusion rate to two-thirds (66.67%) for capital gains realized above $250,000 annually for individuals, effective June 25, 2024. For corporations and trusts, the two-thirds rate applies to all capital gains without the $250,000 threshold. As of this writing, this change has been introduced and investors with significant capital gains should verify the current rules with a qualified tax advisor, as the legislative environment has been subject to political developments.

For most Ontario individual investors realizing gains under $250,000 in a year, the longstanding 50% inclusion rate continues to apply. For those realizing larger gains, the higher inclusion rate on the excess becomes a real planning consideration.

What Is Your Effective Tax Rate on Capital Gains?

In Ontario, the highest marginal personal income tax rate is approximately 53.53%. Applied to the 50% inclusion rate, the effective tax rate on capital gains (below the $250,000 threshold) is approximately 26.76% at the top marginal rate. That is significantly below the rate on interest income or employment income.

This favourable tax treatment is one reason why building long-term wealth through capital-appreciating investments can be more tax-efficient than, say, accumulating interest-bearing assets in a non-registered account.

Capital Losses and How to Use Them

A capital loss occurs when you sell an asset for less than its ACB. Capital losses can only be used to offset capital gains — they cannot reduce other types of income like employment income or interest income.

The rules on timing are specific: capital losses realized in a given year can offset capital gains realized in the same year. Any excess net capital loss can be carried back up to three years (to offset gains in those prior years) or carried forward indefinitely.

Superficial loss rule: If you sell a security at a loss and repurchase the same or an identical security within 30 days (before or after the sale), the CRA denies the loss under the superficial loss rules. This is an important trap to avoid if you are harvesting losses for tax purposes.

The Principal Residence Exemption

One of the most valuable provisions in Canadian tax law is the principal residence exemption, which eliminates capital gains tax on the sale of your home. For most Ontario homeowners who have lived in their home as their principal residence for the entire period of ownership, the full gain on the sale is exempt.

Complications arise when you have owned more than one property that could qualify (a cottage, for instance), when you have rented out part of your home, when you have used the property for business, or when you have been a non-resident. Each of these can affect the exemption calculation and must be reported properly.

Deemed Dispositions: When Tax Happens Without a Sale

The Income Tax Act deems certain events to be dispositions even when no actual sale occurs:

Death: At death, you are deemed to have sold all your capital property at fair market value. The resulting capital gains are reported on the terminal return (the final tax return). This can create a substantial tax liability and is a major driver of estate planning strategies.

Leaving Canada: When a Canadian resident emigrates, most assets are subject to a deemed disposition at fair market value.

Transfers to a corporation or trust: Certain transfers can also trigger deemed dispositions unless specific rollovers are available under the Income Tax Act.

Planning Strategies for Ontario Investors

Spread large gains across tax years. Where you have control over the timing of a sale — a private business, real estate, or a large portfolio position — realizing the gain over two or more calendar years can keep the annual inclusion amount below thresholds and within lower brackets.

Use registered accounts strategically. Capital gains inside an RRSP, RRIF, or TFSA do not trigger immediate tax. The TFSA in particular allows tax-free growth and tax-free withdrawal of capital gains.

Donate appreciated securities. If you donate publicly traded securities with accrued gains directly to a registered charity, the capital gain is eliminated and you also receive a donation receipt for the full fair market value. This is often significantly more tax-efficient than selling the securities and donating the cash.

Gift to a lower-income spouse with caution. Income attribution rules generally attribute capital gains back to the higher-income spouse if you gift or lend funds to a lower-income spouse. Proper planning is required to avoid these rules.

At Pineault Wealth Management in London, Ontario, Marc Pineault helps clients understand how capital gains fit into their broader tax and investment strategy — identifying opportunities to manage exposure and avoid common traps that can dramatically increase a tax bill unnecessarily.

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This article is for educational purposes only and does not constitute personalized financial advice. Please consult a qualified financial planner before making any financial decisions.