Borrowing Power Calculator

A borrowing power calculator estimates how much you could borrow based on the repayments you can afford. Enter your income, housing costs, other commitments, an affordability share and an assumed APR to see an estimated loan amount.

By the InstalmentLoans Editorial Team · Last updated 2 October 2026

Get an instalment loan quote Check the repayment first

We may receive a commission from lenders or brokers if you take out a loan through a link on this site. This does not affect the amount you repay.

WARNING: Late repayment can cause you serious money problems. For help, go to moneyhelper.org.uk

Enter your numbers and press Calculate. Nothing you type leaves your browser.

How this calculator works

Borrowing power is the loan amount that a given monthly repayment supports at a given rate and term.

Income available = gross monthly income * affordability share.

Monthly amount for the loan = income available - other monthly commitments.

Borrowing power P = M * (1 - (1 + r)^-n) / r, where r is the annual rate / 12 / 100 and n is the term in months. At 0% this becomes P = M * n.

This is a planning estimate, not an offer. Enter the APR you were quoted; lenders apply their own affordability and credit checks.

Frequently asked questions

How is borrowing power estimated?
The calculator works out how much of your income you could put towards a new repayment, then converts that monthly amount into a loan size using the APR and term you enter.
What affordability share should I use?
That is a modelling choice, not a market figure. Many people test a range such as 30% to 40% of gross income. The lower and higher rows show how sensitive the estimate is.
Is the result the amount I will be offered?
No. It is a planning estimate. A lender's decision depends on your credit history, income evidence, existing debts and its own lending rules.
Does a longer term increase how much I can borrow?
Yes. Spreading the same repayment over more months supports a larger loan, but you pay interest for longer and the total cost rises.

Related calculators