Debt-to-Income Ratio Calculator

This debt-to-income ratio calculator computes both DTI numbers a mortgage lender will run before approving you: your front-end ratio (housing payment ÷ gross monthly income) and your back-end ratio (housing plus every other monthly debt payment ÷ gross monthly income). Enter your before-tax monthly income, your rent or full mortgage payment, and each recurring debt — car loans, credit card minimums, student loans, personal loans, child support — and the calculator shows where you stand against conventional, FHA, and VA loan limits.

When a lender, a bank, or an article says "DTI," they almost always mean the back-end number. The CFPB defines the debt-to-income ratio as all your monthly debt payments divided by your gross monthly income — income before taxes and deductions, which is why your DTI usually looks better than your budget feels.

Everything you enter stays on your device. If your DTI is high, the fastest fix is usually retiring a debt payment entirely — model that in the Debt Payoff Optimizer — or replacing several payments with one smaller one via the Debt Consolidation Calculator. Shopping for a home? Pair this with the Advanced Mortgage Calculator to see the full PITI payment that feeds your front-end ratio.

Both ratios use gross (pre-tax) monthly income as the denominator:

Front-end DTI = monthly housing payment ÷ gross monthly income × 100
Back-end DTI = (housing + all other monthly debt payments) ÷ gross monthly income × 100

The housing payment for a homeowner means the full PITI — principal, interest, property taxes, homeowners insurance — plus HOA dues and any mortgage insurance, not just the loan payment. For renters, it's the rent.

What counts as debt: car payments, minimum credit card payments (the minimum, not what you actually pay), student loans, personal loans, alimony and child support, and payments on any other loans. What doesn't count: utilities, groceries, phone bills, insurance premiums (other than those inside PITI), subscriptions, and taxes — living expenses aren't debts.

Worked example (the calculator's defaults): gross income of $7,500/month, housing of $1,850, plus a $420 car payment, $150 in card minimums, and a $220 student loan payment ($790 of other debt). Front-end: $1,850 ÷ $7,500 = 24.7%. Back-end: $2,640 ÷ $7,500 = 35.2%. That's inside the classic 36% conventional guideline with $585/month of room before hitting the 43% threshold.

Conventional loans historically used the "28/36 rule" — 28% front-end, 36% back-end — as the comfort benchmark. In practice, Fannie Mae's underwriting guidelines allow back-end DTIs up to 45%, and up to 50% with strong compensating factors like significant reserves or excellent credit through automated underwriting.

FHA loans use a 31/43 baseline — 31% front-end, 43% back-end. FHA is notably flexible above those numbers when compensating factors exist (verified reserves, minimal payment shock, residual income), and automated approvals well above 43% are common, which is why FHA remains the path for many higher-DTI borrowers.

VA loans use a 41% back-end guideline rather than a hard cap, because the VA's primary test is residual income — the dollars left after housing, debts, and estimated living expenses, which must clear a regional threshold based on family size. A borrower over 41% DTI with strong residual income can still be approved.

Two practical implications. First, the same borrower can pass FHA and fail conventional, or vice versa — run your numbers against each row in the results. Second, these are underwriting ceilings, not recommendations: a 43% DTI means 43 cents of every pre-tax dollar is spoken for before you eat. Most financial planners treat anything under 36% as the healthy zone.

DTI has exactly two levers — debt payments down or income up — but the tactics differ in speed:

Eliminate a payment entirely (fastest impact per dollar). DTI counts payments, not balances. Paying a $3,000 card down to $2,000 barely moves your minimum; paying off a car loan with 6 payments left erases the entire $420 from the ratio. If you're within a year of finishing any installment loan, finishing it early is often the single biggest DTI improvement available. Sequence this with the Debt Payoff Optimizer.

Consolidate to shrink the monthly figure. Replacing $600 of scattered minimums with one $350 consolidation payment cuts your DTI even if total debt is unchanged — lenders underwrite the payment, not the philosophy. Check the trade-offs in the Debt Consolidation Calculator first, since a longer term can cost more in total interest.

Don't open new credit before a mortgage application. Any new payment lands directly in the numerator, and the hard inquiry dings your score at the worst moment.

Document all income. Bonuses, overtime with a two-year history, a second job, or a co-borrower's income all raise the denominator. Self-employed income counts as the average of your tax-return net, which is why aggressive write-offs can quietly wreck a mortgage application.

Most lenders want a back-end DTI at or below 43% for a mortgage, with 36% considered comfortable. Conventional loans can stretch to 45–50% with strong credit and reserves, FHA baselines are 31% front-end / 43% back-end, and VA loans use a 41% guideline with a residual-income test.

The table below summarizes the thresholds this calculator checks against your numbers:

Remember the housing figure a mortgage lender uses is the complete PITI + HOA payment, not just principal and interest — estimate it with the Advanced Mortgage Calculator, then bring that number back here.

Canadian lenders run the same two-ratio test under different names: GDS (Gross Debt Service — the front-end housing ratio, including heating costs and half of condo fees) and TDS (Total Debt Service — the back-end ratio with all debts). CMHC-insured mortgages generally cap GDS at 39% and TDS at 44%.

You can use this calculator for the Canadian test: enter your housing costs including heat in the housing payment, and your other debts as usual. Front-end ≈ GDS and back-end ≈ TDS. Canadian borrowers must also qualify at the stress-test rate — the higher of your contract rate + 2% or the benchmark floor — so run your mortgage payment at that stressed rate for a realistic TDS.