How a fixed-rate loan payment is estimated
When you borrow a fixed amount at a fixed interest rate and pay it off in equal monthly installments, each payment contains both interest and a reduction of principal. Early payments generally contain more interest, while later payments pay down a greater share of the remaining balance.
This calculator uses the standard amortizing loan formula based on principal, monthly interest rate, and the number of monthly payments. It assumes the quoted rate is a nominal annual interest rate divided by 12. If the annual rate is zero, each payment is simply principal divided by the number of months.
Interest rate is not necessarily APR
Some loan disclosures describe an annual percentage rate, or APR, that incorporates certain loan charges. A disclosed APR may not equal the rate used to compute contractual monthly interest. Enter the stated note rate for a more useful comparison to a lender's payment schedule and examine its separate fee disclosures.
What the total repayment means
Multiplying the monthly principal-and-interest payment by the number of months gives an estimated repayment amount. Total interest is that amount minus the borrowed principal. This assumes you make every payment on schedule and do not add extra principal payments, late fees, variable-rate changes, or refinancing costs.
Why your lender's payment may differ
For a mortgage, the monthly bill may also include property taxes, homeowners insurance, mortgage insurance, HOA charges, or escrow. For other loans, origination fees, final-payment adjustments, daily compounding, or a first payment date may matter. Compare this estimate to a written loan disclosure rather than using it as a binding offer.
Independent educational tool. Calculations are estimates and do not replace a lender statement, payroll advice, tax advice, or legal guidance. Read the disclaimer.