How loan qualifier calculator works
Lenders cap how much of your monthly income can go toward debt payments using a debt-to-income (DTI) ratio. The back-end DTI includes the new loan payment plus all other monthly debt. Your maximum monthly payment is monthlyIncome times the DTI percentage minus your other monthly debt payments.
This calculator takes your monthly income, other monthly debt payments, a target back-end DTI (commonly 43% for conventional loans, 36% for a stricter standard), the loan's annual interest rate, the term in years, and a down payment. It computes the maximum monthly payment, the maximum loan amount (the present value of that annuity at the given rate and term), and the maximum home price (max loan plus down payment).
If your other debts already eat up the DTI allowance, the tool reports that the loan is not affordable at that ratio — a clear signal to lower the DTI target, pay down debt, or increase income. All math runs in your browser; it is an estimate, not a loan offer.
Frequently asked questions
What DTI should I use?
43% is the top back-end DTI most conventional lenders will allow for a qualified mortgage, while 36% is a stricter traditional standard. A lower DTI leaves more room for the payment and raises the qualifying loan amount if your debts are small; a higher DTI tightens it.
What counts as other monthly debt?
Include recurring monthly obligations that appear on a credit report: car payments, student loans, minimum credit-card payments, child support, and any other installment debt. Do not include living expenses like groceries, utilities, or insurance.
Does this include property taxes and insurance?
No. This calculator isolates the loan payment itself. Real mortgage payments add property taxes, homeowners insurance, and mortgage insurance (PITI), which also count against your DTI — so in practice the qualifying loan will be a bit lower than this estimate.
Is the result a loan offer?
No. It is a quick estimate of the ceiling a lender might use. Actual approval depends on credit score, employment history, the property, reserves, and the lender's overlays. Treat it as a planning guide, not a commitment.
