Debt to Income Ratio Calculator UK & US — Are You Mortgage Ready?
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Get My Credit Score Roadmap →The mortgage broker asked me for my debt-to-income ratio. I did not know what that was. I certainly did not know that the car finance, the credit cards and the personal loan I was quietly paying off every month had pushed mine to 47% — well above what most high street lenders want to see. I was declined. Not because I could not afford the mortgage. Because my DTI said I could not.
Lenders use two DTI figures — front-end (housing costs only) and back-end (all monthly debt payments). Both matter. This calculator gives you both, tells you where you stand against UK and US lender thresholds, and shows you exactly which debt to clear first for the biggest DTI improvement.
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Mathematical Estimation — not a lending decision.
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Enter your email and we will send your front-end and back-end DTI, your mortgage readiness verdict, and which debt to clear first.
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UK Lender DTI Thresholds — 2026
What UK mortgage lenders want to see
High street banks: Back-end DTI under 40%. Front-end under 35%. Most lenders stress-test at 3% above the current rate.
Building societies: Often more flexible — some will accept up to 45% back-end DTI for strong applicants with clean credit history.
Specialist lenders: May accept up to 50% DTI with compensating factors such as large deposit, strong income or no dependants.
Self-Employed DTI — Important Difference
UK mortgage lenders typically use your last two to three years’ average net profit for self-employed applicants — not your turnover. Some specialist lenders will use just one year’s accounts. Always use your average net profit figure in the calculator — not your turnover or gross income — for the most accurate DTI calculation.
How to Reduce Your DTI Before a Mortgage Application
Clear the debt with the highest monthly payment first
DTI is calculated on monthly payments — not total balances. A personal loan with 18 months remaining and a £300/month payment does more damage to your DTI than a larger credit card balance with a £75 minimum payment. The calculator ranks your debts by DTI impact and tells you which to clear first.
Do not take on new debt before applying
Any new credit agreement — car finance, personal loan, new credit card — adds to your monthly obligation and raises your DTI. Do not apply for any new credit in the six months before a mortgage application.
High DTI from multiple debts?
Get your exact payoff order and see how quickly your DTI improves as each debt clears. Free debt payoff planner.
Get My Free Payoff Plan →Frequently Asked Questions — DTI Ratio Calculator
What is a good debt to income ratio in the UK?
Under 36% back-end DTI is considered good by most UK lenders. Under 20% is excellent. Between 36%–40% is acceptable for most high street lenders. Above 40% will limit your options to specialist lenders with higher rates.
Does my student loan count toward my DTI?
For UK mortgage applications — yes. Your monthly student loan repayment is included in lenders’ affordability calculations even though it does not appear on your credit file. Enter your current monthly deduction in the student loan field for an accurate DTI figure.
Does BNPL affect my DTI?
From July 2026 — yes. FCA-regulated BNPL agreements now appear on your credit file. Lenders increasingly include active BNPL commitments in their affordability calculations. Include any regular BNPL monthly payments in the Other field for the most accurate result.
What is front-end DTI vs back-end DTI?
Front-end DTI includes only your housing costs — rent or mortgage payment — divided by your gross monthly income. Back-end DTI includes all monthly debt obligations — housing plus credit cards, loans, car finance, student loan and BNPL. Lenders look at both. Most focus primarily on back-end DTI.
How quickly can I improve my DTI?
Each debt you clear in full removes that monthly payment from your DTI immediately. If you clear a £300/month personal loan, your back-end DTI drops by that amount relative to your income instantly. Use our AI Debt Payoff Planner to model how quickly each debt payoff improves your overall position.
Related reading: How to Improve Your Credit Score · Credit Utilisation Calculator · Savings vs Debt Calculator
Disclaimer: DebtShift is an educational platform. Results are mathematical estimations. Not a lending decision or financial advice. Lenders assess applications individually — DTI is one of many factors considered. DebtShift is not FCA regulated.