Lenders do not ask what you can afford; they apply two ratios. Housing costs are capped at around 28% of gross income, and all debt payments together at around 36%. Whichever binds first sets your limit. Enter your income, existing debts and deposit to see the number a lender would arrive at, and which of the two rules is holding you back.
The front-end ratio caps housing costs - mortgage, tax and insurance - at 28% of gross monthly income. The back-end ratio caps every debt payment combined, including car loans, student loans and credit card minimums, at 36%. Lenders vary these, and government-backed loans often allow more, but they are the standard starting point.
Because the back-end ratio counts it. A 400 a month car payment removes 400 from the budget the 36% rule allows, and at typical rates that is worth roughly 60,000 to 70,000 of mortgage. Clearing a debt often moves the number more than a pay rise does.
Rarely. The ratios describe what a lender will risk, not what leaves you comfortable. They ignore childcare, pensions, saving and the running costs of a larger home. Many people find a payment around 25% of take-home pay far easier to live with than one at the 28% of gross that the rule permits.