A mortgage is likely the largest loan you'll ever take, so understanding the payment is essential. This calculator turns a home price, down payment, rate and term into your monthly payment, total interest and a full amortization schedule.
How the payment is built
A fixed-rate mortgage is amortized: you pay the same amount every month, split between interest (charged on the remaining balance) and principal (which pays down the loan). Because the balance is highest at the start, early payments are mostly interest, and the mix shifts toward principal over time.
The formula
Monthly payment M = P·r·(1+r)^n / ((1+r)^n − 1), where P is the principal, r is the monthly rate (annual rate ÷ 12), and n is the total number of payments (years × 12). Lower any of rate, principal or term and the payment falls.
The true cost of homeownership
Principal and interest are only part of the picture. Property taxes, homeowners insurance, PMI (if your down payment is under 20%), HOA dues and ongoing maintenance can add 25–40% on top of the base payment. Budget for all of it before you buy.
Ways to pay less
Increase your down payment, secure a lower rate by shopping lenders and improving your credit, choose a shorter term, or make extra principal payments early — when they have the biggest impact on total interest.
Frequently asked questions
It uses the amortization formula: M = P·r·(1+r)^n / ((1+r)^n − 1), where P is the loan amount, r is the monthly interest rate (APR ÷ 12), and n is the number of monthly payments. This calculator does it for you.
This tool calculates principal and interest. Your actual monthly bill often also includes property tax, homeowners insurance, PMI (if under 20% down) and any HOA fees.
20% is a common target because it usually removes PMI and lowers your payment, but many loans allow far less. A bigger down payment reduces both your monthly cost and total interest.
A 15-year term has higher monthly payments but much lower total interest and faster equity. A 30-year term is more affordable monthly but costs more overall. Pick based on your budget and goals.