Guide
Mortgage Payments — P&I, Term Length & Total Interest
A mortgage calculator answers the first question most buyers ask: what is the principal-and-interest payment on this loan? Taxes, insurance, and HOA dues sit on top of P&I — add them separately for a full housing budget.
Updated September 15, 2026
What the payment covers
Fixed-rate P&I uses the same amortizing math as EMI: a constant monthly payment over the term. The rate and term you enter drive both the monthly bill and lifetime interest.
Escrow for property tax and homeowners insurance can add hundreds per month depending on location; PMI/MIP may apply with low down payments.
How to use the calculator
Enter loan amount, annual interest rate, and term in years (commonly 15 or 30).
Read monthly P&I, total interest, and the amortization chart or year-by-year table.
How to read the numbers
Monthly payment here is principal + interest only.
A 15-year term usually means a higher payment and far less total interest than 30 years at the same rate.
Use the schedule to see when principal repayment overtakes interest.
Common mistakes
Treating P&I as the full housing cost and forgetting escrow.
Entering APR (with fees) instead of the amortizing note rate.
Assuming an ARM stays at the initial rate for the full term.
Worked example
On a $300,000 loan at 6.5% for 30 years, monthly P&I is about $1,896. Lifetime interest is on the order of $383,000 if you never prepay — before taxes and insurance.
Mirror those inputs in the Mortgage Calculator, then try 15 years to compare payment versus interest trade-offs.