House Affordability Calculator

Only principal and interest (P&I). It does not include property taxes, homeowner's insurance, PMI, HOA fees, or maintenance, so the real total monthly housing cost will usually be higher than the figure shown.

A common conservative target is 36% (the front-end + back-end DTI rule of thumb), so that is the default. Many lenders allow higher ratios — sometimes 43% to 50% depending on the loan program — but a lower DTI leaves more room in your budget for taxes, insurance, and life.

The calculator inverts the standard fixed-rate amortization formula: P = M × (1 − (1 + r)^−n) / r, where M is your max monthly P&I budget, r is the monthly rate, and n is the number of monthly payments. Zero-interest loans use P = M × n.