Debt-to-Income (DTI) Calculator
Work out the debt-to-income ratio lenders use when underwriting a mortgage, car loan, or refinance. Splits housing-only (front-end) from total (back-end) DTI and flags the band you fall in.
Debt-to-income ratio
33.33%
- Front-end DTI (housing only)
- 25%
- Total monthly debt
- £2,000.00
- Income after debt payments
- £4,000.00
- Lender band
- Healthy (≤36%)
Back-end DTI divides every recurring debt payment — housing, loans, minimum card payments, support obligations — by gross (pre-tax) monthly income. Front-end DTI looks at housing only. Most mortgage lenders prefer back-end DTI ≤ 36%, will stretch to 43% on a conforming loan (the old CFPB Qualified Mortgage threshold), and treat anything above 50% as high risk. Use gross, not net, income — that is what lenders underwrite against.
How to use this calculator
Enter your gross (pre-tax) monthly income — what shows on your offer letter or self-employment net before income tax, not your take-home pay. Enter your monthly housing payment: mortgage principal + interest + property tax + homeowners insurance + HOA if you own, or rent if you do not. Enter every other recurring debt obligation: car loans, student loans, personal loans, the minimum payment on each credit card, child support, and alimony. Leave out utilities, groceries, insurance premiums not bundled into housing, and discretionary spend — lenders do not count them in DTI.
How the calculation works
Two ratios. Back-end DTI = (housing + other recurring debt) / gross monthly income × 100; this is the headline number lenders quote and the one the calculator returns as the primary result. Front-end DTI = housing / gross monthly income × 100; lenders look at it separately to size your housing burden. The calculator also reports your monthly income after debt payments — the cash left to cover living expenses, savings, and tax — and the lender band: ≤36% healthy, 36–43% manageable (43% was the old CFPB Qualified Mortgage cap), 43–50% stretched, above 50% high risk.
Worked example
A household earns $6,000 a month gross. Mortgage P&I + tax + insurance = $1,500. Car loan $300, student loan $150, credit card minimums $50 — $500 other debt. Total monthly debt = $2,000. Back-end DTI = 2,000 / 6,000 = 33.3% (healthy). Front-end DTI = 1,500 / 6,000 = 25%. Income after debt payments = $4,000 to cover taxes, food, utilities, savings, and life.
Frequently asked questions
What counts as debt in DTI?
Recurring, contractual obligations that show up on a credit report: mortgage or rent, car loans, student loans, personal loans, the minimum payment on each credit card, court-ordered child support and alimony. Do not include utilities, food, fuel, health insurance premiums (unless bundled into payroll), cell phone bills, or savings contributions — none of those are debt and none of them are counted by lenders. Property taxes and homeowners insurance only count when they are escrowed into the mortgage payment, which is the standard convention.
Gross or net income — which do I use?
Gross, every time. Underwriting runs against gross monthly income because it is the only figure that is independent of where you live (state and local income tax vary), what benefits you elect, and how much you contribute to retirement plans. For W-2 employees that is annual salary ÷ 12. For self-employed borrowers it is the trailing 24-month average of net profit from Schedule C or K-1, not bank deposits — lenders pull this off tax returns.
What is a good DTI ratio?
Below 36% is the conventional comfort zone — you have enough income left over to absorb a job loss or rate shock without skipping payments. 36–43% is acceptable to most conforming-mortgage lenders; 43% was the explicit cap under the CFPB Qualified Mortgage rule from 2014 to 2021 and is still the threshold many manual underwriters anchor on. Above 43% you are into non-QM and manual-underwrite territory; above 50% most lenders will decline outright, regardless of credit score or down payment.
What is the difference between front-end and back-end DTI?
Front-end DTI counts only your housing payment (PITI plus HOA) against income; back-end DTI counts every recurring debt. The front-end ratio sizes your housing burden in isolation — conventional underwriting prefers it ≤28%, FHA up to 31%. The back-end ratio measures total debt load. A borrower with low front-end DTI but high back-end DTI carries a lot of consumer debt; lenders see that as a sign new credit may be hard to service if rates move or income drops.
How do I lower my DTI quickly?
Two levers: cut the numerator (monthly debt) or grow the denominator (income). Numerator cuts work fastest — pay off the smallest balances first to eliminate full minimum payments (a $20/month card minimum kills more DTI per dollar paid down than $20 chipped off a 30-year mortgage), refinance high-rate consumer debt into a longer-amortising loan, or roll multiple debts into a single lower-payment consolidation. Denominator growth is slower but durable: document a raise, a second job, or self-employment income with two years of tax returns to make it underwritable.
Does this calculator handle UK / Europe / Australia?
The formula is universal — pre-tax monthly income on the bottom, recurring debt obligations on top — and the calculator is geography-neutral. The bands shown (36 / 43 / 50) come from US conforming-mortgage convention, but UK lenders apply broadly similar guidelines: most mainstream UK mortgages cap total debt-to-income around 40–45%, with the Bank of England loan-to-income test capping at 4.5× income for the bulk of new lending. Australian responsible-lending guidelines look at similar ratios. Use the number as a directional check; your specific lender will publish its own cut-offs.