Debt-to-Income Ratio Calculator

Debt-to-income, often shortened to DTI, is a quick way to see how much of your monthly income is already spoken for by debt and housing payments. This UK debt-to-income calculator adds up rent or mortgage, credit cards, loans, car finance and other payments, then compares them with gross monthly income.

How to use this debt-to-income calculator

Enter your gross annual income before tax, then add your regular monthly debt payments. Use minimum credit card payments if you are checking your monthly affordability. If you want to see how long a balance may take to clear, use our debt payoff calculator or credit card payoff calculator. If the ratio is linked to housing, compare it with the rent affordability calculator or mortgage affordability calculator.

The formula explained in plain English

Debt-to-income equals monthly debt payments divided by gross monthly income, multiplied by 100. If you earn £45,000 a year, your gross monthly income is £3,750. If your rent, cards, loans and car finance total £1,470 a month, your DTI is 39.2%. The calculator also shows your housing ratio and non-housing debt ratio so you can see what is driving the number.

Worked example

A person earning £45,000 has £3,750 gross monthly income. Their rent is £950, credit card payments are £120, a personal loan is £180 and car finance is £220. Total monthly payments are £1,470. Divide £1,470 by £3,750 and multiply by 100, giving a debt-to-income ratio of 39.2%. That sits in the moderate band used by this calculator.

Common mistakes people make

One mistake is using take-home pay in a formula designed around gross income. Take-home pay is useful for budgeting, but DTI is usually described against gross income. Another mistake is excluding buy-now-pay-later or car finance because it feels smaller than a loan. If it is a regular required payment, include it. Our compound interest explained guide shows why debt costs can grow quickly, and our mortgage affordability guide explains why lenders do not use one ratio alone.

Related calculators

Try the debt payoff calculator to plan repayments, the credit card payoff calculator for card balances, the rent affordability calculator for renting, and the mortgage affordability calculator for buying.