Canada Mortgage and Housing Corporation guidelines cap gross debt service, your housing costs as a share of income, at around 39 percent, and total debt service, housing plus all other debt payments, at around 44 percent. A buyer with a car loan or student debt qualifies for less house than one with the same income and no other debt.
A larger down payment reduces the mortgage amount and therefore the income needed to qualify, which is one reason stacking a Home Buyers' Plan withdrawal with an FHSA can meaningfully change what a first-time buyer can afford. Property tax and heating costs also factor into the ratio, so a home with high utility bills can lower your qualifying amount even at the same price.
A mortgage broker can run your actual numbers against these ratios before you start touring, which is a more useful exercise than any general income rule. Get your hand-reviewed valuation from Joel Dyck.