Debt to Income Calculator
A debt-to-income (DTI) calculator determines the percentage of your gross monthly income that goes toward debt payments. Lenders use DTI to assess your ability to manage mortgage payments.
DTI Ratio Types
| Ratio | What It Measures | Formula | Front-End (Housing)Housing costs only(PITI) / Gross Income Back-End (Total)All debt payments(Total Debt) / Gross Income
DTI Requirements by Loan Type
Loan TypeMax Front-EndMax Back-End Conventional28%36-43% FHA31%43% VANone41% USDA29%41% | Jumbo | 28% | 36% |
DTI Calculator Implementation
``javascript
function calculateDTI(grossMonthlyIncome, monthlyDebts) {
// monthlyDebts object: { housing, carLoan, studentLoan, creditCards, other }
const housing = monthlyDebts.housing || 0;
const totalDebt = Object.values(monthlyDebts).reduce((sum, d) => sum + d, 0);
const frontEndDTI = (housing / grossMonthlyIncome) * 100;
const backEndDTI = (totalDebt / grossMonthlyIncome) * 100;
let status;
if (backEndDTI <= 36) status = 'Excellent - easily qualifies';
else if (backEndDTI <= 43) status = 'Good - qualifies for most loans';
else if (backEndDTI <= 50) status = 'Fair - may qualify with compensating factors';
else status = 'Poor - unlikely to qualify';
return {
frontEndDTI: frontEndDTI.toFixed(1) + '%',
backEndDTI: backEndDTI.toFixed(1) + '%',
status,
maxAffordableHousing: ((grossMonthlyIncome * 0.28) - housing).toFixed(2)
};
}
const income = 8000;
const debts = { housing: 1800, carLoan: 400, studentLoan: 300, creditCards: 100 };
console.log(calculateDTI(income, debts));
// { frontEndDTI: '22.5%', backEndDTI: '32.5%', status: 'Excellent' }
``
Improving Your DTI
Lower DTI by paying off debt (especially high-payment items like car loans), increasing income, or buying a less expensive home. Avoid new debt before applying for a mortgage.