How much can I borrow against rental income in Ontario?

In Ontario, how much rental income adds to what you can borrow depends on who sets the rule. For a CMHC-insured mortgage on a 2–4 unit property, CMHC's published rules let up to 100% or up to 50% of the gross rent count, depending on the number of units and whether you live there. For a rental you won't live in, the mortgage is generally uninsured and each lender uses its own method, commonly adding a share of the rent to your income or offsetting a share against the property's costs. No one can name your amount until a lender has your application, and any amount is subject to lender approval.

What rent changes, and what it doesn't

Rent doesn't change how qualifying works; it changes the numbers going in. Lenders check two ratios. GDS (gross debt service) is your housing costs as a share of your gross income. TDS (total debt service) is your housing costs plus your other debts. For insured mortgages the limits are 39% and 44%, calculated at the qualifying rate, the stress test (source: Canada Mortgage and Housing Corporation, checked October 2026).

Rent counted as income raises the income side of those ratios. Rent offset against costs lowers the cost side. Either way, the more of the rent a lender counts, generally the more room you have.

How CMHC counts rent on insured 2–4 unit properties

CMHC publishes how rent counts on the mortgages it insures (source: Canada Mortgage and Housing Corporation, Rental Income, published May 2024, checked October 2026). The rules below are the insurer's, not any one lender's:

You live in a 2-unit property: up to 100% of the gross rent may be added to your income.
You live in a 3- or 4-unit property: up to 50% of the gross rent, or a net approach, where costs are subtracted from the rent first. With the gross-rent option, the property's taxes and heat may be left out of your housing costs.
You don't live in a 2–4 unit property: up to 50% of the gross rent, or the net approach.
A single-unit rental: not eligible for CMHC mortgage loan insurance.

A worked example with an insured duplex

Illustrative, not a quote. You earn $90,000 a year and are buying a duplex with a CMHC-insured mortgage. You will live in one unit; the other rents for $1,800 a month.

Gross rent: $1,800 × 12 = $21,600 a year. Up to 100% may count.
Qualifying income: $90,000 + $21,600 = $111,600.
Without the rent, the 39% GDS limit allows about $2,925 a month of housing costs ($90,000 × 39% ÷ 12). With the rent, about $3,627 ($111,600 × 39% ÷ 12).
The rent adds about $700 a month of room for principal, interest, property tax and heat.

How much mortgage that $700 supports depends on the qualifying rate and the amortization. Your other debts still have to fit under the 44% TDS limit.

How lenders generally count rent on other rentals

A property you buy purely to rent out generally needs at least 20% down (the down payment for a rental), so the mortgage is usually uninsured and the lender's own method applies. Banks, credit unions and monoline lenders commonly use one of two approaches:

Add-back: a share of the rent is added to your income.
Offset: a share of the rent is set against the property's own costs, and what is left, positive or negative, generally feeds into your ratios.

The share and the method vary by lender and property type. Lenders also often check whether the rent covers the property's own costs. Where the rent doesn't cover those costs, the property generally reduces what you can borrow elsewhere (when a rental doesn't cover its costs).

Because the methods differ, the same rental can support different amounts at different lenders, so comparing lenders matters here.

What you can work out yourself

The rental cash-flow tool takes the rent, expenses, vacancy and mortgage payment and shows the cash flow, a coverage read and how lenders generally treat the rent. The tool shows the inputs a lender looks at; it does not tell you what a lender will approve.

What to do next

Put your own numbers into the rental cash-flow tool first. To see how lenders would treat the rent on a specific property, use our call-back form and bring your plan, not just the listing. Any amount is subject to lender approval.

Common follow-up questions

Does rent from a unit that isn't rented yet count?

Often, with an appraiser's estimate of market rent, though some lenders count less without a signed lease. Ask the lender before you rely on that rent.

Does rent from my other properties count too?

Yes, but differently. For an insured mortgage, CMHC uses a net approach for rentals other than the one you are buying: rent less operating expenses, with that property's principal, interest, taxes and heat deducted or counted as a debt. A negative result counts against you (source: Canada Mortgage and Housing Corporation, checked October 2026).

Will a bigger down payment let me borrow more?

Partly: a bigger down payment can help the coverage check, but not the share of rent counted. More down lowers the mortgage you need and the payment the rent has to cover. The share of the rent a lender counts stays the same.