Will This Loan Hurt My Mortgage Approval?
A new loan hurts a mortgage approval mainly through its payment: it goes into your debt-to-income ratio, and every program has a line that ratio must stay under. Put in your income, the mortgage payment, your other debts and the loan, and see the ratio with and without it, program by program, including whether a loan with only a few payments left counts at all.
Your debt-to-income ratio, with and without the loan
Monthly figures, before tax. The ratio is every monthly debt payment, the new mortgage included, divided by gross monthly income.
Principal, interest, taxes, insurance, mortgage insurance and HOA dues. Work it out.
Car and student loans, card minimums, child support. Not utilities, phone or groceries.
A loan you are thinking of taking, or one already open. Find its payment.
- Without the loan
- Housing alone (front ratio)
- Room under 43% with the loan
Program by program
| Program | The line | Your ratio | Verdict |
|---|
The published lines only. A lender's own limits can be lower, automated underwriting weighs the whole file, and income, debts and the payment are as the lender counts them. Ask your loan officer before you take on a loan.
What goes into the ratio
Debt-to-income is your monthly debt payments, the new mortgage's full payment included, divided by your gross monthly income: pay before tax. The mortgage payment is principal and interest plus property tax, homeowners insurance, mortgage insurance and any HOA dues. The debts are the ones on your credit report and application: car and student loans, personal and installment loans, the minimum payment on each card, child support and alimony. Utilities, phone, insurance on the car and groceries are not debts here. The front ratio is the housing payment alone over income; FHA and USDA set a line for it too.
An example: $6,000 a month, a $1,800 mortgage payment and $400 of other debts is a 36.7% ratio. A $200-a-month installment loan with a year to run takes it to 40.0%. That still fits Fannie Mae's DU line, FHA's 31/43 and VA's 41%, but a manually underwritten conventional loan now needs the credit score and reserves Fannie Mae asks for above 36%. With housing alone at 30%, USDA's 29% line was crossed before the loan.
The lines
| Program | Housing alone | All debts | Source |
|---|---|---|---|
| Conventional, Fannie Mae, through DU | - | 50% | B3-6-02 |
| Conventional, manually underwritten | - | 36%; up to 45% with the credit score and reserves in Fannie Mae's Eligibility Matrix | B3-6-02 |
| FHA, manually underwritten | 31% | 43%; 37/47 with one compensating factor, 40/40 with no discretionary debt, 40/50 with two; 31/43 only below a 580 score | HUD 4000.1 |
| VA | - | 41%, with residual income checked as well | 38 CFR 36.4340 |
| USDA | 29% | 41% | 7 CFR 3555.151 |
FHA's compensating factors are verified cash reserves, a minimal increase in housing payment, significant income not counted, and residual income. An FHA loan approved by its automated scorecard is not held to the manual matrix; HUD publishes no single ratio for it. VA rounds the ratio to a whole number (35.6% is 36%), and above 41% approves with residual income at least 20% over its guideline or a supervisor's written justification.
When a short loan is left out
Each program has its own rule for a loan that will soon be paid off, and they differ at the edges:
- Fannie Mae: installment debt counts "if there are more than ten monthly payments remaining," and one with fewer "also should be considered" if it "significantly affects the borrower's ability to meet their credit obligations."
- FHA: a closed-end debt is left out only "if it will be paid off within 10 months from the date of closing and the cumulative payments of all such debts are less than or equal to 5 percent of the Borrower's gross monthly income." And "the Borrower may not pay down the balance in order to meet the 10-month requirement."
- VA: the significant debts are those "of a relatively long term, i.e., 10 months or over"; shorter ones "must, of course, be considered" in the family budget.
- USDA: the total-debt ratio takes "recurring monthly debts"; the checker counts the loan, and your lender will say if its handbook leaves a short one out.
So a loan with exactly ten payments left can be outside the ratio for a Fannie Mae loan and inside it for VA. Paying off an installment loan before you apply and the large deposit rule cover what a payoff leaves on your statements.
A loan taken after approval
Approval is not the finish line. Fannie Mae tells lenders that if new debt comes to light before closing, the ratio is worked out again, and "if the recalculated DTI ratio exceeds 45% for a manually underwritten loan or 50% for a DU loan casefile, the loan is not eligible." A manually underwritten loan pushed over 36% must then meet the higher score and reserve requirements. The checker warns when the loan you enter crosses either line. Denied after pre-approval, clearing conditional approval and what not to do before closing are the guides on this.
The installment loan calculator works out a loan's payment and passes it here. The mortgage calculator works out the housing payment.
Sources: Fannie Mae Selling Guide B3-6-02 and B3-6-05; HUD Single Family Housing Policy Handbook 4000.1 (closed-end debts; approvable ratio requirements, manual); 38 CFR 36.4340 (VA); 7 CFR 3555.151(h) (USDA). Read October 2026. These are the agencies' published lines; a lender's own overlays can be stricter, and automated underwriting weighs the whole file. General information, not a loan decision.