Mortgage Calculator
Calculate your monthly mortgage payment. Enter loan amount, interest rate, and term to see your payment and total interest paid.
How to calculate Mortgage
A mortgage is typically the largest financial commitment of a person's life, so understanding exactly how your monthly payment is calculated is essential before signing any paperwork.
The monthly payment formula is M = P[r(1+r)^n] ÷ [(1+r)^n − 1], where P is the loan principal, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (years × 12).
For a $300,000 loan at 6.5% over 30 years: r = 0.065/12 = 0.00542, n = 360 payments, giving a monthly payment of approximately $1,896. Over 30 years you pay $382,560 — meaning $82,560 goes to interest alone.
A 15-year mortgage has higher monthly payments but far less total interest. Even small rate differences have enormous long-term effects: a 0.5% rate reduction on a $300,000 loan saves roughly $30,000 over 30 years.
This calculator shows your monthly payment, total amount paid, and total interest over the life of the loan. Always use these numbers alongside a full amortisation schedule from your lender.