Home Affordability Calculator

Home Affordability Calculator works from the same arithmetic a lender uses. A proportion of your gross monthly income is allowed for all debt, your existing commitments are subtracted, property tax and insurance come out of what is left, and whatever remains is the mortgage payment you can support. Reversing the payment formula turns that into a loan, and adding your deposit turns the loan into a price.

The debt-to-income limit is the number that moves the answer most. Thirty-six per cent is the conventional ceiling for total debt and the usual default; some lenders stretch to forty-three for a strong application, and some cap housing costs alone at twenty-eight. The table runs all of them so you can see the range rather than one answer with a false air of precision.

A word on what this does not measure. It tells you what you are likely to be lent, which is not the same as what you should borrow. The limit counts your debts but knows nothing about childcare, commuting, savings you want to keep up, or how secure the income is. Borrowing the maximum is a decision; being able to is only a fact.

This is arithmetic, not financial advice. It tells you what the numbers do; it cannot tell you whether a decision is right for your circumstances. Fees, taxes and local rules vary, so check anything that matters against the actual offer and speak to someone qualified before committing.

Everything is worked out inside your browser. Nothing you enter is uploaded, logged or stored, which matters for the financial calculators in particular: the figures you put into them are nobody else's business.

• Shows price you can afford, mortgage that supports, monthly housing budget, of that, loan payment and deposit as a share of price together, so you are not running it twice
• A results table you can read across
• Updates as you type, with no button to press and no page reload
• Copy the result in one click
• Free, no sign-up, and it runs entirely in your browser

The home affordability calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

• Setting a realistic budget before viewing properties
• Seeing what clearing a car loan does to your buying power
• Working out how much more deposit changes the price range
• Checking a broker's figure against the standard ratios