What Is Your Debt-to-Income Ratio? (UK Calculator and Guide)
Your DTI ratio affects mortgage approvals, credit card offers, and your financial health. Here's how to calculate yours and what the benchmarks mean.
TL;DR
DTI ratio = monthly debt payments / gross monthly income. Below 20% is excellent, 20-35% is manageable, 36-43% is a warning, above 50% means get free advice. Reducing DTI before a mortgage application can improve rates and borrowing limits.
Your debt-to-income ratio is one of the first things lenders look at when you apply for a mortgage, loan, or credit card. It's also one of the most useful numbers for understanding your own financial situation. Here's how it works and what yours means.
What is the debt-to-income ratio?
It's the percentage of your gross monthly income that goes toward debt repayments. If you earn £2,500 per month and spend £600 on debt payments (credit cards, loans, car finance, minimum payments), your DTI ratio is 24 per cent.
The calculation itself is simple: total monthly debt payments divided by gross monthly income, multiplied by 100. The tricky part is knowing what counts as debt. Credit cards, personal loans, car finance, student loan repayments, and BNPL commitments all count. Rent and utility bills generally don't, though mortgage lenders sometimes factor them in separately.
UK benchmarks: where do you stand?
Below 20 per cent is considered excellent. You're comfortably managing your debt and lenders will generally offer you their best rates.
Between 20 and 35 per cent is manageable. Most lenders are still happy to work with you, though you might not get the absolute best deals. This is where the average UK borrower sits.
Between 36 and 43 per cent is a warning zone. You'll find it harder to get approved for new credit. Some mortgage lenders will still consider you, but your options narrow.
Above 50 per cent is high risk territory. You're spending more than half your income on debt. At this level, it's worth speaking to a free debt adviser to review your options.
Why your DTI matters for mortgages
UK mortgage lenders don't always use the DTI ratio in the same way American lenders do, but they absolutely look at your existing debt commitments as part of their affordability assessment. If you're paying £400 per month on a car loan and £200 on credit cards, that's £600 per month the lender knows isn't available for mortgage payments.
Reducing your DTI before applying for a mortgage can make a real difference to what you're offered. Paying down a credit card or clearing a small loan before your application could mean a better interest rate, a higher borrowing limit, or both.
How to lower your DTI ratio
There are really only two levers: reduce your debt payments or increase your income. On the debt side, paying off the smallest balances first is often the quickest way to free up cash, even if the interest rate isn't the highest. Use our Debt Payoff Calculator to compare strategies.
If you can't pay down debts quickly, consolidating them into a lower monthly payment can reduce your DTI ratio. Just watch the total cost, because extending the term might lower the monthly payment while increasing total interest paid.
On the income side, a pay rise, side work, or even including a partner's income on a joint application can all improve your ratio.
Calculate yours
Use our Debt-to-Income Calculator to get your ratio in about 30 seconds. It breaks down exactly where you stand against the benchmarks above and suggests what to focus on.
From there, you can use the Budget Planner to find money to put toward debt, or set a target debt-free date with our Debt-Free Date calculator. If your ratio is above 50 per cent, free confidential advice is available from StepChange (0800 138 1111) and National Debtline (0808 808 4000).
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This article is for informational purposes only and does not constitute financial advice. For personalised guidance, speak to a qualified financial adviser or contact a free UK debt charity: StepChange (0800 138 1111) or National Debtline (0808 808 4000).