Quick answer
Your debt-to-income ratio is your monthly debt payments divided by your gross monthly income — the first number a mortgage lender checks. With gross pay of $7,200 a month and $2,730 of housing and debt payments, your back-end DTI is 37.9%: inside most lending limits, but above the 36% line lenders prefer. The housing-only (front-end) ratio here is 25.7%.
How the Debt-to-Income Ratio Calculator works, step by step
Add up monthly debt payments as a lender counts them: the full housing payment (principal, interest, tax, insurance, HOA), car loans, student loans, minimum payments on credit cards, personal loans and any court-ordered payments. Divide by gross monthly income — before tax, because that is the lender convention, generous as it feels.
Two ratios come out. The front-end ratio counts housing only; lenders look for roughly 28% or less. The back-end (total) ratio counts everything, and the calculator bands it: 36% or less is comfortable, 37% to 43% acceptable for most programmes, 44% to 50% stretched and needing strong compensating factors, above 50% high risk.
What is not counted surprises people: utilities, groceries, insurance premiums (other than those inside the housing payment), subscriptions and rent (unless you are applying while renting and it appears as an obligation). Only debts on the credit report and the application count — which is why a $160 card minimum payment matters more to your mortgage than a $400 grocery bill.
The calculator also shows your headroom against each threshold. In the example you could take on about $366 more a month before crossing 43%, but you are already $138 a month over the comfortable 36% line. Paying off the $430 car loan before applying drops the back-end ratio to 31.9% — often a better use of cash than a slightly larger down payment, because it also raises the loan amount the ratio allows.
Run the ratio on take-home pay as well, for your own budgeting. The worked example's 37.9% of gross is about 50.6% of a typical take-home figure — the share of actual cash committed before food, fuel or anything else — which is the number that decides whether the budget breathes. Lenders use gross; your household lives on net.
The formula
Front-end DTI = monthly housing costs ÷ gross monthly income × 100. Back-end DTI = (housing costs + all monthly debt payments) ÷ gross monthly income × 100. Headroom to a threshold = (gross income × threshold %) − total monthly debts.
Worked example — try it on the calculator above
Worked example: $86,400 salary, applying for a mortgage
Gross monthly income: $7,200. Payments: housing $1,850, car loan $430, credit card minimums $160, student loan $290 — total $2,730. Back-end DTI = $2,730 ÷ $7,200 = 37.9%. Front-end = $1,850 ÷ $7,200 = 25.7%. The calculator bands 37.9% as acceptable but above the 36% comfort line, with $366 a month of headroom to 43%. Paying off the car loan before applying removes $430 and drops the back-end ratio to 31.9% — comfortably inside the zone most lenders prefer, and worth considerably more to the application than the same cash added to the deposit.
Frequently Asked Questions
What DTI do I need to qualify for a mortgage?
It varies by programme. Fannie Mae allows up to 50% back-end DTI through its automated Desktop Underwriter system (36% for manually underwritten loans, up to 45% with strong credit and reserves). FHA's standard is 31% housing and 43% total for manual underwriting, higher with compensating factors or an automated approval. VA and USDA use 41% as a benchmark. Lenders may overlay their own caps.
Is 43% still the legal DTI limit for a qualified mortgage?
No — the CFPB removed the 43% cap from the Qualified Mortgage rule in its December 2020 final rule, with mandatory compliance from October 1, 2022, replacing it with a price-based test (the loan's APR versus the average prime offer rate). The 43% figure survives as a lender guideline and as this calculator's planning line, but it is no longer a federal limit.
How can I lower my DTI quickly?
Pay off small installment debts outright — removing a $430 car payment helps more than paying $10,000 off a card balance whose minimum only falls slightly. Lenders often exclude an installment debt with under 10 payments remaining. Increasing documented income (a second job held for two years, rental income) counts too, but cannot be manufactured quickly.
Does DTI affect my credit score?
Not directly — income is not part of a credit report, so the ratio never appears in scoring. But the ingredients overlap: high card balances raise both your utilisation (lowering your score) and your minimum payments (raising your DTI). Paying balances down improves both numbers at once, which is why it is the standard pre-mortgage advice.
Estimates, not advice. This calculator provides educational estimates based on the inputs you enter and the assumptions shown on this page. It is not financial, tax or investment advice, and it cannot see your full situation. Verify important figures against official sources, and consider a qualified professional for decisions about your own money. See our Disclaimer and Methodology.