Plot No. 27 · Money & Finance
Debt-to-Income Ratio Calculator
Work out your debt-to-income ratio, the share of your gross monthly income that goes on debt payments. Add your rent or mortgage, car or loan payments, credit card minimums and other debt, then divide the total by your gross monthly income and multiply by 100. Lenders use this percentage to judge how much new borrowing you can handle.
Lenders use gross income (before tax) and may weigh some debts differently. Treat the band as a guide, not a guaranteed lending decision.
The link saves your inputs so you can bookmark or share this exact result.
How the debt-to-income ratio is worked out
Your debt-to-income ratio is the share of your gross monthly income swallowed by debt payments. The calculator adds your rent or mortgage, car or loan payments, credit card minimums and other debt to get total monthly debt, then divides that by your gross monthly income and multiplies by 100. The result is a percentage, and lower is better.
Lenders lean on this number because it shows how much room you have to take on more borrowing. The bands used here are 36% or below as healthy, 37% to 43% as manageable but tight, and above 43% as high. It uses gross income (before tax) so the figure matches what a mortgage or loan provider would calculate.
How to use the debt-to-income ratio calculator
- Enter your gross monthly income, your pay before tax and deductions, not your take-home figure.
- Add each recurring debt payment: rent or mortgage, car finance, credit card minimums and any other loans.
- Read the percentage and band, then test how clearing a card or loan would move you into a healthier zone.
Worked examples
Right at the healthy edge
Inputs: Income 4,000; rent 1,100, car 250, card minimums 90, other 0
Result: Total monthly debt 1,440 divided by 4,000 is 36.0%, exactly at the top of the healthy band.
Tipping into high
Inputs: Same debts but income falls to 3,000
Result: 1,440 divided by 3,000 is 48.0%, which lands in the high band and would likely limit new borrowing.
Limitations and common mistakes
Edge cases and limitations
- It uses your stated minimum card payments. Paying only the minimum keeps the ratio low but lets interest build, so a low DTI does not always mean healthy finances.
- Lenders weigh some commitments differently and may add others, so your real assessment can differ from this guide.
- Day-to-day costs like food, utilities and childcare are excluded because they are not classed as debt, even though they affect affordability.
Common mistakes
- Using net (take-home) pay instead of gross income, which makes the ratio look worse than the one lenders see.
- Leaving out a debt such as student loan repayments or a buy-now-pay-later plan, understating the true ratio.
Frequently asked questions
What is a good debt-to-income ratio?
As a rough guide, 36% or below is healthy, 37% to 43% is manageable but tighter, and above 43% is high and may limit new borrowing. With the default figures here (£1,440 of monthly debt on £4,000 gross income) the ratio is exactly 36%, right at the top of the healthy band.
Is DTI based on gross or net income?
Lenders almost always use gross income, which is your pay before tax and other deductions. This calculator does the same so your figure matches what a mortgage or loan provider would work out. If you used take-home pay instead, your ratio would look higher than the one lenders see.
Which debts count towards DTI?
Include recurring debt payments: rent or mortgage, car finance, personal and student loans, and the minimum payment on credit cards. Day-to-day spending like groceries, utilities and subscriptions is usually left out because it is not classed as debt.
Related calculators
UK Salary Take-Home Calculator
Estimate your monthly take-home from a UK gross salary using simplified 2025 tax bands.
Mortgage Repayment Calculator
See your monthly mortgage payment and total interest over the life of the loan.
FIRE Retirement Calculator
Find out when you can retire based on savings, monthly investing and target spend.
Loan Amortization Calculator
Year-by-year breakdown of principal and interest for any fixed-rate loan.
See all money & finance calculators.