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6 min readNumbers only. No advice.

How Much House Can I Afford? The Core Maths Behind the Question

A broader affordability explainer covering salary, debts, deposit, rate, tax, and insurance assumptions that shape home-price limits.

Read the formula, then test the same idea with your own inputs.
Use the Mortgage Affordability Calculator

This extension page exists to support specific long-tail queries with formula-first explanations. It is intentionally narrow, deliberately opinion-free, and designed to lead into the relevant calculator rather than replace it.

Plain Figures does not recommend products, wrappers, or financial actions here. The goal is to make the arithmetic and the assumptions visible.

Core Formula

Affordability framing
Affordable home approx. borrowing capacity + deposit, subject to debt-to-income and payment-stress constraints
  • Income defines debt capacity
  • Existing debt payments reduce headroom
  • Deposit changes purchase price and LTV
  • Taxes and insurance can reduce the repayment budget

Why this query stays strong

How much house can I afford is one of the clearest high-intent finance queries because it sits close to a real transaction.

That makes it worth serving with a dedicated formula-first page even when a calculator already exists.

Why the answer is multidimensional

This query is often simplified into a salary multiple, but that hides too much. Debt obligations, deposit, rate assumptions, and lender policy all reshape the answer.

A good explainer clarifies the structure first and lets the calculator handle the detailed scenario work second.

FAQ

Is affordability just a salary multiple?

No. Income multiples are only a starting point; debts, deposit, rates, and lender stress tests also matter.

Should I use this or the mortgage calculator first?

Use affordability first to find a range, then mortgage repayment to understand the monthly cost within that range.

Disclaimer

Illustrative only. Affordability content here is educational and not a mortgage pre-approval, recommendation, or financial advice.
Use This Calculator

Open the matching calculator to apply the guide to your own numbers.

Use the Mortgage Affordability CalculatorRun your own numbers with the linked calculator after reading the formula-first explanation.
Attribution and Review
Published by the Plain Figures editorial team. Review on this site focuses on formula accuracy, assumption clarity, and threshold freshness where current-year rules matter.
MethodologyAuthors and ReviewEditorial Policy
Related Guides

Keep moving through the same topical cluster with nearby explainers that support the calculator.

Read How Mortgage Affordability Is AssessedRead How Mortgage Repayment Calculations WorkRead Rent vs Buy: The Key Numbers to Compare
This guide is for general information only. Plain Figures does not provide financial advice. All figures are illustrative. Formulas and tax rules change, so verify current rates and consult a qualified adviser before making decisions.