Calculate your DTI ratio — the key number lenders check before approving a mortgage or loan.
Add this Debt-to-Income Ratio Calculator to your website or blog for free — just paste this code:
This debt-to-income ratio calculator shows lenders' single most important affordability figure: the share of your gross monthly income that goes toward debt payments. It is built for anyone applying for a mortgage, car loan or refinance who wants to know where they stand before a bank pulls their file.
Your debt-to-income ratio, or DTI, is calculated with a straightforward formula: total monthly debt payments ÷ gross monthly income × 100. Gross income is your pay before tax and deductions. Debt payments include the minimums on credit cards, student loans, car loans, personal loans and any existing mortgage or rent that the lender counts.
Lenders often look at two versions. The front-end ratio counts only housing costs, while the back-end ratio counts all recurring debt including the proposed new payment. The back-end figure is the one most commonly used for mortgage approval, which is why lowering other balances before you apply can make a real difference.
Most lenders prefer a DTI below 43%. A ratio under 36% is considered healthy, and under 20% is excellent.
Divide your total monthly debt payments by your gross monthly income and multiply by 100. For example, £1,500 debts on £5,000 income = 30% DTI.
DTI itself is not directly part of your credit score, but high debt payments relative to income can make it harder to make on-time payments, which affects your score.
Many mortgage programs cap total DTI around 43%, though some allow higher with strong credit or reserves. Staying at or below 36% gives you the widest choice of lenders and rates.