Mortgage Payment Calculator
Calculate the monthly principal and interest payment on any U.S. mortgage — a 30-year fixed, a 15-year fixed, or an adjustable-rate loan. The calculator uses the standard amortization formula and shows the total interest paid over the life of the loan, so you can see the true cost of stretching the term.
How is this calculated?
Monthly P&I uses the standard amortization formula: M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1], where P is the loan amount, r is the monthly rate (annual rate ÷ 12), and n is the number of monthly payments. The result is the principal-and-interest portion only — your full PITI payment also includes property tax (which varies by county/state), homeowners insurance, and PMI if your down payment is below 20%. Property tax and insurance figures should be confirmed with your county assessor and insurer.
Frequently Asked Questions
How are U.S. mortgage payments calculated?
Lenders use the standard amortization formula. Each monthly payment covers interest accrued on the outstanding balance plus a portion of principal. Early in a 30-year fixed mortgage, the vast majority of each payment is interest; by year 20 the split has flipped and most of each payment reduces principal.
What is a typical U.S. mortgage rate in 2026?
Average 30-year fixed rates in 2026 sit broadly in the 6%–7% range, tracking the 10-year Treasury yield rather than the Federal Funds Rate directly. 15-year fixed rates typically run 0.5–0.75 percentage points lower. Rates vary by credit score, loan-to-value, and loan type (conventional, FHA, VA, jumbo).
What does PITI mean?
Principal, Interest, Taxes, and Insurance — the four components of a typical full monthly housing payment. Lenders use PITI when calculating debt-to-income ratios for qualification. Property tax varies sharply by county and state, and homeowners insurance varies by region and coverage level.
How much does a $400,000 mortgage cost per month?
At 6.5% over 30 years, a $400,000 mortgage costs roughly $2,528 per month in principal and interest, with about $510,000 in total interest paid over the term. A 15-year mortgage at the same rate costs about $3,486 per month but cuts total interest to around $228,000 — a $282,000 saving.
Last updated: May 2026 · Rates sourced from IRS