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Mortgage Affordability Calculator
How much house can you actually afford? The maximum price you can qualify for from your income, debts, and down payment, with Canada's stress test or the US 28/36 rule built in.
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How rates change what you can afford
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About this calculator
This affordability calculator works the way a lender does, in reverse. It starts from your gross income and existing debt payments, applies the qualifying limits for your country, and solves for the largest home price whose mortgage you could be approved for with your down payment.
In Canada, it caps your housing costs (stress-tested mortgage payment, property tax, heat, and half of condo fees) at a 39% GDS ratio and your housing plus other debts at a 44% TDS ratio, then qualifies you at the minimum qualifying rate: the greater of your contract rate plus 2% or 5.25%. It also enforces minimum-down-payment tiers (5% of the first $500K, 10% up to $1.5M, 20% at $1.5M+), and adds the CMHC-style insurance premium (4.0%, 3.1%, or 2.8% of the loan, plus 0.2% for amortizations over 25 years) to the mortgage when your down payment is under 20%.
In the USA, it applies the 28/36 guideline: housing costs (payment, property tax, insurance, HOA, and PMI if under 20% down) up to 28% of gross monthly income, and total debt up to the back-end ratio you choose (36% by default). You pay and qualify at the same rate; there is no US stress test.
Affordability FAQ
What is the Canadian mortgage stress test?
To qualify for a mortgage in Canada you must prove you could afford payments at the minimum qualifying rate: the greater of your contract rate plus 2% or 5.25%. You pay your actual contract rate, but the higher test rate limits how much you can borrow. This calculator applies it automatically.
What are GDS and TDS ratios?
GDS (gross debt service) is the share of gross income going to housing: mortgage payment, property tax, heat, and half of condo fees. TDS (total debt service) adds all other debt payments. For insured mortgages in Canada the limits are 39% GDS and 44% TDS.
What is the 28/36 rule?
A common US lending guideline: spend no more than 28% of gross monthly income on housing and no more than 36% on housing plus all other debts. Many lenders approve higher back-end ratios, sometimes into the mid-40s; use the ratio field to see how much difference that makes.
How much down payment do I need in Canada?
At least 5% of the first $500,000 and 10% of the portion between $500,000 and $1.5 million. At $1.5 million or more you need 20% down, because default insurance isn't available above that price. Under 20% down, the insurance premium is added to your mortgage principal.
Who can use a 30-year amortization in Canada?
For insured mortgages (under 20% down), 30-year amortizations are available to first-time buyers and buyers of newly built homes, with a 0.2% insurance premium surcharge. With 20% or more down, many lenders offer 30 years to anyone. A longer amortization lowers the payment and raises what you qualify for, but costs more interest over time.
Should I borrow the maximum?
The maximum is what a lender might approve, not what leaves room to live. Budgeting below the limit leaves space for rate rises at renewal, repairs, and life. Try the Rent vs Buy calculator to sanity-check the decision itself.