What determines an affordable mortgage?
Mortgage affordability in Canada depends on more than income. Lenders typically review qualifying income, required debt payments, the proposed mortgage payment, property tax, heating costs and a portion of condominium fees. They may also test the mortgage payment at a higher qualifying rate than the rate the borrower is expected to pay.
Cash requirements create a separate limitation. A household may be able to support the monthly payments for a particular mortgage but still lack the down payment and closing funds needed to complete the purchase. This calculator evaluates both sides and uses whichever result is more restrictive.
The result is an estimate. A lender must verify the information, assess the property and apply the rules of the selected mortgage product before issuing an approval.
How this affordability estimate is assembled
The calculator begins by converting gross annual household income into a monthly amount. It then calculates the maximum housing budget permitted by the entered gross debt service (GDS) limit.
Property tax, heating and 50% of entered condominium fees are deducted from that housing budget. The remainder represents the mortgage-payment capacity under the GDS test.
A second calculation applies the total debt service (TDS) limit. It deducts required payments for debts such as vehicle financing, credit cards, student loans and lines of credit. Whichever test leaves less room for a mortgage payment becomes the binding debt-service result.
The permitted payment is converted into an estimated mortgage principal using the qualifying rate, selected amortization and Canadian mortgage-compounding assumptions. The model then checks whether the savings remaining after the chosen reserve can cover the down payment and estimated purchase costs.
GDS examines housing costs
Gross debt service compares defined housing expenses with gross household income. CMHC’s standard insured-mortgage calculation commonly uses a maximum of 39%, although an application may be assessed differently.
TDS includes other debts
Total debt service adds required non-housing debt payments to the housing costs used in the calculation. CMHC’s standard insured-mortgage maximum is commonly 44%, subject to underwriting requirements.
The qualifying rate tests resilience
The mortgage payment used for qualification may be calculated at the higher of the contractual rate plus two percentage points or the applicable qualifying-rate floor. This is not necessarily the rate charged to the borrower.
A household budget answers a different question
GDS and TDS are underwriting measurements based on gross income. Your personal budget must work with take-home income and expenses that lending ratios may not fully capture.
Why qualification and personal comfort can differ
A lender’s debt-service calculation evaluates mortgage qualification under defined rules. It is not designed to build a complete household spending plan. Costs such as food, transportation, childcare, communication services, maintenance and savings goals may not receive the same treatment in lending ratios.
The monthly take-home income field provides a separate household-budget view. The calculator deducts the entered housing and debt costs to show an estimated remaining amount. A positive result does not guarantee that the mortgage is comfortable; it simply provides another figure for the user to assess.
Consider how the budget would respond to higher renewal rates, temporary income loss, major repairs or growing family expenses. A purchase price below the mathematical maximum may leave more flexibility for these changes.
Understanding the Canadian mortgage stress test
Federally regulated lenders generally qualify mortgage borrowers using a prescribed minimum qualifying rate. Under the current framework, the calculation commonly uses the greater of:
- the mortgage contract rate plus two percentage points; or
- the applicable minimum qualifying-rate floor.
The default floor in this calculator is 5.25%. The requirement can be reviewed or changed, and its application can depend on the mortgage transaction. Users should therefore check the current OSFI minimum qualifying rate and the FCAC mortgage preparation guidance .
The stress-test payment is used to assess the application. The payment actually charged under the mortgage is normally based on the contract rate and agreed payment schedule.
How GDS and TDS treat housing expenses
In the model, the GDS housing total contains the stress-tested mortgage payment, property tax, heating and half of the entered condominium fees. The TDS total begins with those costs and adds the monthly debt payments entered by the user.
The optional “other homeowner expenses” figure is used for the personal cash-flow illustration, not the standard GDS or TDS test. This prevents maintenance and insurance estimates from being incorrectly presented as standard components of the qualifying ratios.
CMHC provides additional details about calculating GDS and TDS ratios .
Down payment, insurance and funds needed at closing
The down payment is deducted from the purchase price to determine the base mortgage. For an eligible purchase with less than 20% down, mortgage default insurance is generally required. The premium protects the lender and is commonly added to the mortgage principal.
Adding the premium to the mortgage means it can affect the payment and debt-service calculations. Provincial sales tax on the insurance premium, where applicable, may need to be paid separately rather than financed.
Insured-mortgage eligibility is not determined by the down payment alone. Purchase-price limits, property requirements, borrower eligibility and permitted amortization periods also apply. Selecting 30 years in this calculator does not mean every insured borrower or property qualifies for that amortization.
The calculator also reserves an estimated amount for closing. Actual expenses can include legal services, title insurance, land-transfer or property-transfer taxes, inspections, appraisals, tax adjustments and moving costs. Their amount varies by location and transaction.
What the target-home check can tell you
The main estimate works backwards from income, debts and available cash to produce a possible price range. The target-home section asks the opposite question: does a particular price and down payment fit the assumptions entered?
It compares the planned down payment with the modelled minimum, estimates any mortgage-insurance premium and calculates the mortgage payment at the qualifying rate. It then reports GDS, TDS and estimated cash needed.
The adjustment section illustrates how the scenario might change with a larger down payment, reduced monthly debt, additional income or a lower contract rate. These figures are mathematical comparisons—not recommendations or promises that the revised application would be approved.
To examine the payment schedule after choosing a mortgage amount, use the Canada mortgage calculator.
Practical Canadian mortgage affordability questions
My lender offered 4.75%. Why does the calculator test me at a higher rate
The contract rate estimates the payment you may actually make, while the qualifying rate tests whether the mortgage remains supportable at a higher rate. With a 4.75% contract rate and a two‑percentage‑point buffer, the model would use 6.75% because that is higher than the 5.25% floor.
Why can a car payment reduce my possible mortgage
A required vehicle payment is included in total debt service. It uses part of the monthly debt capacity that might otherwise be available for the qualifying mortgage payment.
Are GDS and TDS the same as a personal budget
No. They are underwriting ratios built from gross income and defined housing and debt expenses. A personal budget should also account for income tax, food, transportation, childcare, maintenance, savings and other household costs.
Does a larger down payment always increase the affordable price
It can reduce the required mortgage and may reduce or eliminate the mortgage-insurance premium. However, the purchase may still be limited by the income-based GDS or TDS calculation. Closing costs and emergency savings must also remain available.
Why does the calculator include only half of my condo fees in GDS and TDS
The model follows the common insured-mortgage convention of including 50% of condominium fees in the debt-service calculation. A lender or insurer may apply its own current requirements.
Can I qualify for a 30-year amortization
Eligibility depends on the mortgage type, down payment, borrower, property and current insurance rules. The calculator lets you model 30 years, but selecting it does not establish eligibility.
Why does the calculator keep an emergency reserve
The reserve prevents all entered savings from being treated as purchase money. Keeping funds after closing may help cover moving costs, repairs, income interruptions and other unexpected expenses.
Does the maximum result mean I should spend that amount
No. It is an estimated upper range under the selected assumptions. A lower purchase price may provide more room for lifestyle costs, savings, future rate changes and property maintenance.
Is this calculation a mortgage pre-approval
No. A pre-approval or final decision requires verification of income, employment, debts, credit, down-payment sources and other information. Final approval also depends on the property and lender requirements.