{"tool":{"slug":"dti","name":"Debt-to-income ratio calculator","version":"2026-08-21","canonicalUrl":"https://carlo.finance/tools/dti?income=150000&housing=2500&debts=400","jsonUrl":"https://carlo.finance/tools/dti.json?income=150000&housing=2500&debts=400","pageUrl":"https://carlo.finance/tools/dti","parameters":[{"key":"income","label":"Annual gross household income","unit":"usd-per-year","min":0,"max":100000000,"default":100000,"sourceId":null,"help":"Before taxes, everyone whose income would go on the application. The default is an example, not a statistic."},{"key":"housing","label":"Monthly housing payment","unit":"usd-per-month","min":0,"max":1000000,"default":2000,"sourceId":null,"help":"Rent today, or the full house payment: principal, interest, tax, insurance, dues. The default is an example."},{"key":"debts","label":"Other monthly debt payments","unit":"usd-per-month","min":0,"max":1000000,"default":500,"sourceId":null,"help":"Minimum payments on cards, car loans, and student loans. Not utilities or groceries. The default is an example."}]},"inputs":{"income":150000,"housing":2500,"debts":400},"result":{"monthlyIncome":12500,"monthlyDebt":2900,"leftOver":9600,"frontEnd":0.2,"backEnd":0.232,"band":"within-36","lines":[{"pct":36,"label":"36%","meaning":"The manual-underwriting ceiling every program accepts.","allowed":4500,"headroom":1600,"over":0},{"pct":45,"label":"45%","meaning":"Allowed with credit score and reserve requirements.","allowed":5625,"headroom":2725,"over":0},{"pct":50,"label":"50%","meaning":"The Desktop Underwriter maximum; not every borrower gets it.","allowed":6250,"headroom":3350,"over":0}],"maxHousingAt36":4100,"maxHousingAt45":5225},"drivers":[{"key":"debts","label":"Other monthly debt","step":-100,"pointsDelta":-0.8,"sentence":"Paying off $100 of monthly minimums takes 0.8 points off the back-end ratio."},{"key":"housing","label":"Housing payment","step":-100,"pointsDelta":-0.8,"sentence":"A housing payment $100 lower takes 0.8 points off both ratios."},{"key":"income","label":"Income","step":5000,"pointsDelta":-0.75,"sentence":"Earning $5,000 more a year takes 0.75 points off the back-end ratio."}],"sensitivity":{"byDebts":[{"debts":0,"backEnd":0.2,"headroomAt36":2000},{"debts":250,"backEnd":0.22,"headroomAt36":1750},{"debts":500,"backEnd":0.24,"headroomAt36":1500},{"debts":1000,"backEnd":0.28,"headroomAt36":1000}],"byIncome":[{"income":113000,"backEnd":0.308,"frontEnd":0.2655},{"income":135000,"backEnd":0.2578,"frontEnd":0.2222},{"income":150000,"backEnd":0.232,"frontEnd":0.2},{"income":165000,"backEnd":0.2109,"frontEnd":0.1818},{"income":188000,"backEnd":0.1851,"frontEnd":0.1596}]},"assumptions":[{"key":"income","label":"Annual gross household income","value":150000,"unit":"usd-per-year","provided":true,"source":null},{"key":"housing","label":"Monthly housing payment","value":2500,"unit":"usd-per-month","provided":true,"source":null},{"key":"debts","label":"Other monthly debt payments","value":400,"unit":"usd-per-month","provided":true,"source":null}],"sources":[{"id":"dti","name":"Fannie Mae Selling Guide B3-6-02, Debt-to-Income Ratios","url":"https://selling-guide.fanniemae.com/sel/b3-6-02/debt-income-ratios","asOf":"2025-04-02","note":"Manually underwritten loans: maximum total DTI 36%, up to 45% with credit score and reserve requirements. Desktop Underwriter: maximum 50%."}],"warnings":[],"disclaimer":"This compares your debt payments to your gross income the way a mortgage underwriter does, with the ratio limits Fannie Mae publishes. It is not a loan approval, a rate quote, or financial advice. Credit score, reserves, residual income, and program overlays change the real answer."}