Debt-to-Income (DTI)
Front-end and back-end DTI vs FNMA / FHA / VA underwriting thresholds.
Example
You enter
- Gross monthly income ($) 7500
- Housing payment (PITI + HOA, $) 2100
- Other monthly debts ($, car / cards / student / etc.) 600
You get
- Front-end DTI (housing only) 28%
- Back-end DTI (total debt) 36%
Checked against published worked examples from: FNMA / FHA / VA underwriting guidelines (public).
Details, formula, and sources
Formula or tableFront-end DTI = housing_payment / gross_monthly_income. Back-end DTI = (housing + other_debts) / gross_monthly_income. Thresholds per FNMA Selling Guide §B3-6-02 (no front-end ratio; total 36 manual, up to 45 with credit/reserves (the pass flag), 50 through DU), FHA Handbook 4000.1 §II.A.5 (default 31/43), VA Lenders Handbook M26-7 (back-end 41; no front-end limit).
Source and editionFNMA Single-Family Selling Guide §B3-6-02 (current). FHA Handbook 4000.1 §II.A.5. VA Lenders Handbook M26-7.
Free accessFree at selling-guide.fanniemae.com, hud.gov, and benefits.va.gov.
What governsEstimate. Lender governs final underwriting and rate / fee disclosure. Appraiser governs the appraised value. State law and the agency's program guidelines may impose stricter limits than the published thresholds.
API field namesgross_monthly_income, housing_payment, other_monthly_debts, front_end_dti_percent, back_end_dti_percent
- Income basis gross monthly income (pre-tax)agency convention
- Housing payment PITI plus HOA per FNMA conventionFNMA Selling Guide §B3-6-03