Debt-to-Income Calculator — How to Calculate Your DTI Ratio
Estimate front-end and back-end debt to income from your income and monthly debt payments. For planning only — not a loan approval tool.
Income & monthly obligations
Front-end DTI = housing ÷ income. Back-end DTI = (housing + all debts) ÷ income.
Front-end DTI
27.7%
Conservative (under 28%)
Back-end DTI
37.7%
Elevated (36–43%)
Total monthly obligations: $2,450.00
Many lenders use 36% back-end and 28% front-end as reference lines — actual underwriting varies by loan type and lender.
Path to the lender lines
What your monthly payments would need to do to reach each reference line at this income.
Reduce monthly payments by $110.00 — for example by paying off debts whose payments add up to that amount. Max obligations at this line: $2,340.00/mo.
Already under this line, with $345.00/mo of headroom before a new payment would cross it.
DTI ratios for planning only — lenders may count income and debts differently than this estimate. Not a loan approval tool.
When checking your DTI is worth it — and when it misleads
Worth checking
- You're three to six months out from a mortgage or auto application and want to know which side of the reference lines you're standing on.
- You're deciding which debt to pay off first specifically to qualify — the payment size, not the balance, is what moves the ratio.
- You're weighing a new monthly obligation and want to see the after picture before signing, not after.
Where it misleads
- You're comparing total debt loads. DTI only sees monthly payments, so a large balance behind a small minimum can hide inside a good-looking ratio.
- Your income swings month to month. Lenders average or discount variable income, so one strong month makes the ratio look better than underwriting will.
Worked examples
Both runs use the calculator above — enter the same numbers and you'll get the same results.
The page defaults, read out loud
$6,500 gross monthly income, $1,800 housing, $650 of other monthly debt payments
Front-end DTI is 27.7% and back-end is 37.7%. To reach the 36% line, monthly payments need to drop by $110 — max obligations at 36% of this income are $2,340 against $2,450 today.
Retiring one small installment payment often covers a gap this size — the balance doesn't matter, the monthly payment does.
Testing a car payment before signing
Same income and debts, then adding a $450 new-car payment vs a $250 used-car payment
The $450 payment pushes back-end DTI to 44.6% — over the 43% Qualified Mortgage line. The $250 payment lands at 41.5%, staying under it.
If a mortgage application is anywhere on the horizon, this is the math to run in the car lot parking lot, not after.
How this is calculated
Front-end DTI uses housing payment ÷ gross income. Back-end DTI adds other monthly debt payments to housing, divided by gross income. For a written walkthrough of how to calculate debt to income ratio, see our DTI how-to guide.
DTI ratio
DTI % = monthly debt payments ÷ gross monthly income × 100We use the income and debts you enter — not a credit pull or lender rules.
CFPB mortgage underwriting guides · Our methodology →
Where the lender lines actually sit
These are commonly cited planning references, not promises — underwriting weighs income type, credit, reserves, and loan program together.
| Rule or program | Reference line | What it means |
|---|---|---|
| 28/36 planning rule | 28% front · 36% back | The classic conservative reference many planners and conventional lenders start from. |
| Qualified Mortgage (QM) | 43% back-end | CFPB ability-to-repay framework's best-known line; exceptions and other pathways exist. |
| FHA | ~31% front · ~43% back | Commonly cited guideline; approvals above it happen with compensating factors like reserves or strong credit. |
| VA | ~41% guideline | VA leans on residual income — what's left after obligations — more than the ratio itself. |
| Conventional with strong credit | up to ~45–50% back-end | Automated underwriting sometimes approves higher DTI when credit, reserves, and down payment are strong. |
Common traps
DTI counts payments, not balances.
A $10,000 card at a $200 minimum weighs less in the ratio than a $6,000 loan at $350 a month. To move DTI fastest per dollar, retire the debts with the largest payment relative to what's left on them — often an installment loan near the end of its term.
Use gross income, not take-home.
Lenders divide by pre-tax income. Entering your net pay overstates the ratio and can talk you out of an application you'd actually clear.
Not every bill is a debt.
Utilities, phone plans, insurance premiums, and subscriptions generally stay out of the numerator. Student loans count even in deferment — lenders often impute a payment from the balance when the statement shows $0.
Joint applications combine everything.
A co-borrower brings their income and their debts. Run the ratio both ways before assuming a second income fixes it.
Related calculators
The fastest way to move the ratio is retiring an entire payment — the debt payoff calculator shows which of your debts disappears first under a snowball or avalanche plan.
Common questions
Add your monthly debt payments, divide by gross monthly income, then multiply by 100. Front-end uses housing only; back-end adds other debts. This calculator does both — see our how-to-calculate-debt-to-income guide for a step-by-step walkthrough.