Mortgage Calculator

Estimate your monthly mortgage payment, total interest cost, and full amortization schedule.

How the mortgage calculator works

A fixed-rate mortgage spreads your loan across equal monthly payments using the standard amortization formula: the payment is set so that principal plus interest retires the balance exactly at the end of the term. The calculator converts your annual rate to a monthly rate, counts the number of payments in the term, and solves for the payment that zeroes the balance.

Although the payment stays the same every month, what it buys changes. Early on, most of each payment covers interest on the large outstanding balance; over time the balance shrinks, interest charges fall, and an ever-larger share goes to principal. The amortization chart shows this crossover year by year.

Keep in mind the result is principal and interest only. Your actual housing payment will also include property taxes, homeowners insurance, possibly private mortgage insurance (PMI), and HOA dues — often grouped as PITI.

How to use this calculator

Enter the loan amount — the purchase price minus your down payment.
Enter the annual interest rate quoted for the loan.
Choose the loan term in years (30 and 15 are the most common).
Press Calculate to see your monthly payment, total interest, and the year-by-year principal vs. interest breakdown.

Key terms

Principal: The amount you borrow. Each payment reduces it a little more than the last.
Amortization: The schedule that splits each level payment between interest and principal until the loan reaches zero.
PITI: Principal, Interest, Taxes, and Insurance — the full monthly housing cost lenders evaluate, beyond the P&I this calculator shows.

Tips

A 15-year term roughly doubles the speed of principal payoff and can cut total interest by more than half versus a 30-year loan.
Even a 0.25% rate difference matters: compare lenders using the same loan amount and term.
Use the total-interest figure, not just the monthly payment, when weighing how much house to buy.

Frequently asked questions

Does this calculator include taxes and insurance?

No. It calculates principal and interest only. Property taxes, homeowners insurance, PMI, and HOA dues vary by location and lender, so add them separately to estimate your full monthly housing cost.

Why does so much of my early payment go to interest?

Interest is charged on the outstanding balance, which is largest at the start of the loan. As payments chip away at the balance, the interest portion shrinks and the principal portion grows — that is what amortization means.

How can I pay less total interest?

Three levers work: a shorter term, a lower rate, or extra principal payments. Our loan payoff calculator shows exactly how much time and interest an extra monthly payment saves.

Planning further? Try the loan payoff calculator or the debt-to-income ratio calculator.

Loan Payoff Calculator

Find out when your loan will be paid off and how much interest extra monthly payments can save.

Debt-to-Income Ratio Calculator

Calculate your front-end and back-end DTI ratios to see how lenders view your debt load.