Your mortgage should be no more than 28% to 36% of your gross monthly income, depending on your debt load and credit profile. This range balances affordability with long-term financial stability. Lenders use this rule to assess risk, but personal circumstances may require adjustments.
This guideline stems from the front-end ratio, which measures housing costs against income. A mortgage exceeding 36% increases the risk of default, especially during economic shifts. The 28% threshold applies to those with little or no existing debt, while higher debt levels justify a lower cap.
The 28/36 rule is widely cited by the Consumer Financial Protection Bureau (CFPB) and the Federal Reserve. According to the CFPB, borrowers who spend more than 36% of their income on debt-including housing-face higher default rates. The Federal Reserve's 2022 study confirmed that households spending over 30% of income on housing were twice as likely to miss payments during rate hikes.
The 28/36 rule divides your income into two parts. The first, 28%, is the maximum you should spend on housing-related expenses: principal, interest, taxes, and insurance (PITI). The second, 36%, includes all recurring debt-credit cards, car loans, student debt, and housing costs.
If your gross monthly income is $6,000, then 28% equals $1,680. That's the upper limit for PITI. If your total debt payments (including the mortgage) exceed $2,160 ($6,000 × 0.36), lenders may reject your application-even if you qualify under the 28% rule.
For example, a borrower earning $7,500 monthly with $800 in credit card debt and $400 in auto payments has a debt-to-income (DTI) ceiling of $2,700. Subtracting existing debts leaves $1,500 for housing. Even if they could afford $2,100 in PITI, the DTI constraint limits the mortgage to $1,500.
PITI stands for principal, interest, taxes, and insurance. Principal is the amount borrowed. Interest is the cost of borrowing. Property taxes and homeowner's insurance are often escrowed into your monthly payment.
Some buyers assume the mortgage payment is just the principal and interest. But property taxes can add $200-$500 monthly depending on location. Homeowners insurance averages $100-$200 monthly. These costs increase the actual payment beyond the loan amount.
In Toronto, average property taxes on a $800,000 home are $6,200 annually-$517 per month. On a $500,000 mortgage at 5.5% interest, principal and interest total $2,832. Adding taxes and insurance brings the total PITI to $3,549. For someone earning $8,000/month, this is 44% of income-well above the recommended 36%.
Many people believe "I can afford a bigger house" because they qualify for a high loan amount. But approval doesn't equal affordability. A lender may approve a $700,000 mortgage based on income and credit-but the monthly payment may still stretch the household budget.
Another error is ignoring future changes. A variable mortgage rate can rise by 2-3 percentage points over five years. If your current payment is $2,500 at 3.5%, a jump to 6.5% increases the payment by $500 monthly. That can push the housing cost above 36% of income.
Some buyers focus on the down payment and ignore ongoing costs. A 20% down payment reduces the loan size, but it doesn't eliminate property taxes, maintenance, or potential condo fees. Over ten years, these add up to tens of thousands of dollars.
Fixed-rate mortgages offer consistent payments. They're ideal for budgeting. Variable-rate mortgages have lower initial payments but carry interest rate risk. If rates rise, your payment increases.
Adjustable-rate mortgages (ARMs) start low but reset every few years. They're risky for long-term planning. In 2007, many ARMs reset to higher rates, triggering widespread defaults. Today, most lenders avoid offering ARMs to first-time buyers.
| Mortgage Type | Interest Rate Stability | Payment Predictability | Best For |
|---|---|---|---|
| Fixed-Rate | High | High | Borrowers prioritizing stability |
| Variable-Rate | Low | Low | Those with stable income and risk tolerance |
| Adjustable-Rate (ARM) | Medium | Medium | Short-term homeowners or refinancers |
Investment mortgages differ from owner-occupied ones. They typically have higher interest rates and stricter qualifying criteria. The Canada Mortgage and Housing Corporation (CMHC) requires a minimum 20% down payment for investment properties, compared to 5% for primary residences.
I once reviewed a client's application who qualified for a $900,000 mortgage based on income. But their combined debt-student loans, car payments, and credit lines-pushed their DTI to 41%. I advised against accepting the full amount. They settled on $720,000, reducing stress and preserving emergency savings.
Start with your gross monthly income. Multiply by 0.28 to find the maximum PITI. Then subtract existing debt payments. The remainder is your safe mortgage payment.
Use a mortgage calculator with realistic tax and insurance estimates. Input your local property tax rate and insurer's quote. Adjust for inflation-property taxes rise 2-3% yearly.
Run a stress test. Assume a 3% interest rate increase. Does your payment stay within 36% of income? If not, reduce the loan amount. Stress testing is required by Canadian banks for all mortgage applications.
Finally, consider lifestyle. A $2,000 monthly mortgage may be affordable-but if it leaves no room for vacations, emergencies, or retirement savings, it's too high. Your mortgage should support your life, not define it.