Loan / Mortgage Calculator

Calculate monthly payments, total cost, and total interest for any fixed-rate loan or mortgage. The full amortization schedule shows exactly how each payment is split between principal and interest over the life of the loan.

Monthly Payment Formula
Monthly = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1] P = principal r = monthly rate (annual rate ÷ 12) n = total payments (years × 12)

This is the standard fixed-rate loan formula. Each monthly payment is fixed, but the split between interest and principal changes each month. Early payments are mostly interest; later payments are mostly principal — this is called amortization.

How to use
Inputs

Enter the loan amount (principal), the annual interest rate as a percentage, and the term in years. For a mortgage, typical terms are 15 or 30 years.

Monthly payment

This is the fixed amount you pay each month. It stays constant for the life of the loan even though the interest/principal split changes each month.

Total interest

This is how much you pay on top of the original loan. For long mortgages at higher rates this can exceed the original loan amount — a key reason to consider overpaying when possible.

Amortization schedule

Click 'Show Amortization Schedule' to see a month-by-month breakdown. Early payments are mostly interest; over time the principal portion grows. This is called amortization.

Formula
Monthly = P × [r(1+r)^n] / [(1+r)^n − 1] P = principal, r = monthly rate (annual/12), n = total payments (years × 12)
Tips
  • •Even one extra payment per year can save tens of thousands of dollars in interest on a 30-year mortgage.
  • •A shorter term (15 vs 30 years) raises monthly payments but dramatically reduces total interest paid.
  • •Use the compound interest calculator to see how investing the difference between a 15 and 30-year payment might perform.