Mortgage calculators
See what overpaying saves you and how much you could realistically borrow, with the assumptions shown rather than hidden.
- Mortgage overpayment calculator Put in what you can afford each month and see the interest saved and the years knocked off the term. Most lenders allow 10% a year penalty-free
- Mortgage affordability calculator There is no single correct answer to how much you can borrow. Here is the realistic range, and what each level costs per month. Shown as a 4x to 5.5x range, not one number
Why affordability has no single right answer
The FCA withdrew its mandatory affordability stress test in August 2022. Lenders have set their own limits since, and the spread is wide — roughly 4 to 5.5 times income for most applicants, stretching further for large deposits and for some professions. A calculator that answers with one confident number is concealing that spread rather than resolving it.
So the affordability tool here returns a range and names the assumptions behind it. What a lender will actually advance depends on its own affordability model, your committed outgoings, the term you take and the rate you fix at — none of which a calculator can see.
Overpaying is far more predictable, because interest is charged on the balance outstanding. Money paid early avoids interest for every remaining month of the term, which is why a modest overpayment in year two beats a larger one in year fifteen. Most fixed deals permit 10% of the balance each year without an early repayment charge, and that allowance is the thing to check before setting up a standing order.
- Typical income multiple
- 4x to 5.5x
- Usual penalty-free overpayment
- 10% a year
- Mandatory stress test
- Withdrawn 2022
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