Introduction
One of the first and most important questions prospective homebuyers ask is: how much mortgage can I actually afford? The answer depends on multiple factors including your income, existing debts, down payment amount, current interest rates, and the specific qualification criteria of your lender. This guide walks you through the key calculations and concepts to help you arrive at a realistic mortgage budget.
The Debt Service Ratios
Canadian lenders use two primary ratios to determine how much mortgage you can qualify for. The Gross Debt Service (GDS) ratio measures your housing costs as a percentage of your gross monthly income. Housing costs include your principal and interest payment, property taxes, heating costs, and 50% of condo fees if applicable. Most lenders require your GDS ratio to be 39% or below.
The Total Debt Service (TDS) ratio adds all of your monthly debt obligations — housing costs plus car payments, credit card minimum payments, student loans, and other debts — as a percentage of gross monthly income. Most lenders require a TDS ratio of 44% or below. These ratios are calculated using the stress test rate, not your actual contracted rate.
A Simple Affordability Calculation
As a rough guide, Canadian homebuyers can typically qualify for a mortgage of approximately 4 to 4.5 times their gross annual household income, assuming minimal other debts. A household with a combined annual income of $150,000 might qualify for a mortgage in the range of $600,000 to $675,000, before factoring in the size of their down payment.
This is a rough guide only — the actual amount you qualify for will depend on current interest rates, the stress test rate, your specific debt load, and your lender’s policies. The most reliable way to know your actual qualifying amount is to go through a formal mortgage pre-approval process.
The Difference Between Can Qualify and Should Borrow
An important distinction to keep in mind is that the maximum amount you qualify for may be more than you should actually borrow. Qualifying for a $700,000 mortgage does not mean that taking on $700,000 in debt is the right financial decision for you. Consider leaving room in your budget for unexpected expenses, home maintenance costs, and life changes. A good rule of thumb is to target a monthly mortgage payment that represents no more than 28% to 32% of your gross monthly income, which is somewhat more conservative than the maximum GDS ratio.
