Mortgage & Loan Calculator

Enter the loan amount, the annual interest rate and the term, and this works out the monthly payment, the total you'll repay, the total interest, and the full month-by-month amortisation schedule behind that number.

Why the payment stays flat but the split doesn't

A standard mortgage or loan is amortised so the monthly payment is identical every month for the whole term — but underneath, the split between interest and principal shifts constantly. Interest is charged on the outstanding balance, which is largest at the very start, so early payments are mostly interest with a small sliver going to principal. As the balance shrinks, that ratio flips, and late payments are mostly principal. On a 30-year mortgage, it typically takes well over half the term before more than half of a single payment goes to principal.

What changing the term or rate actually does

A shorter term raises the monthly payment but cuts total interest sharply, because less time means less balance sitting around accruing interest — dropping a $300,000 loan from 30 to 15 years at the same rate roughly doubles the monthly payment but can cut total interest by more than half. Rate matters more than it looks: on a 30-year term, moving from 6.5% to 7.5% adds well over $100 a month on a $300,000 loan and tens of thousands over the life of the loan.

What this doesn't include

This is principal and interest only. Real mortgage payments (often shown as PITI) also usually include property tax, homeowners insurance, and sometimes mortgage insurance or HOA fees — often adding hundreds of dollars a month on top of the number this calculator shows. Add those separately for the true monthly cost.