You generally won’t know the exact amount you can borrow for a mortgage until you speak to a lender or use a detailed calculator, but you can estimate it quite well by understanding what they look at.

Quick Scoop

Most lenders work backwards from your income, debts, and deposit to decide the maximum mortgage they’re comfortable with, using rules about how big your monthly payment can be compared with your income.

Key factors that decide “how much you can get”

  • Your gross income (salary, bonuses, regular benefits, rental income) is the starting point and usually sets the upper limit on what you can borrow.
  • Your existing monthly debts (credit cards, car loans, student loans, personal loans, child maintenance) reduce how much room is left for a mortgage payment.
  • Your credit score influences the interest rate you’re offered; a better score usually means a lower rate, which allows a larger affordable mortgage for the same income.
  • Your deposit size (or equity if remortgaging) affects loan‑to‑value (LTV): lower LTVs can unlock better rates and sometimes more flexible lending.
  • The interest rate and term length (for example, 25 vs 35 years) change the monthly payment; longer terms lower monthly costs but increase total interest.
  • Lenders also “stress test” affordability by checking if you could still afford payments if rates rise, so they don’t just look at today’s rate.

Typical affordability rules (rough guide)

  • Many lenders cap mortgage costs at roughly 30–36% of your gross monthly income, and all debts (including the mortgage) at about 40–43% of income, though this varies by country and lender.
  • In some markets, you might see older “income multiples” (for example, 4–4.5 times your income), but modern affordability rules focus more on detailed budgets and stress tests than a single multiple.
  • Example: if you earn 3,000 a month, some affordability models say your total debt payments shouldn’t exceed roughly 1,290 a month, with maybe 900 available for the mortgage itself, which then sets a rough borrowing limit at current rates.

How to get your own number today

  • Use an online “how much can I borrow?” or “home affordability” calculator: enter income, monthly debts, deposit and an estimated rate to see a tailored borrowing range and example monthly payments.
  • Try at least two or three different sites (for example, major banks or large comparison sites) to see how assumptions differ and get a realistic range rather than a single figure.
  • Then speak to one or more lenders or a broker to get a pre‑approval in principle; that’s the closest you’ll get to a firm answer before a full application.

Quick HTML table: main drivers of “how much you can get”

Factor How it affects your mortgage amount
Income Higher stable income usually increases the maximum loan you can afford, as lenders base limits on how much of your pay can go to housing.
Existing debts More monthly debt payments shrink what’s left for a mortgage, reducing the amount you can borrow.
Credit score Better scores often unlock lower interest rates and better terms, which can increase your affordable loan size.
Deposit / LTV A larger deposit lowers LTV, can improve rates, and may make lenders more comfortable offering higher amounts.
Interest rate & term Lower rates and longer terms reduce monthly payments, which can raise the ceiling on how much you can borrow.
Stress tests Lenders check if you’d still cope if rates rise, sometimes cutting back the maximum they’re willing to lend.
If you’d like a rough estimate, tell me your country, gross annual income, typical monthly debts, and how much deposit you have, and I can walk you through an approximate borrowing range step by step (not a formal quote, but a useful ballpark).