How to Calculate Your Mortgage Payment
A mortgage payment is calculated using the amortization formula: M = P[r(1+r)^n]/[(1+r)^n-1], where P is the principal loan amount, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments (years multiplied by 12). Enter the loan amount, your annual interest rate, and the loan term in years — the calculator updates your monthly payment instantly. The result is the fixed payment you would make each month for the full loan term.
Mortgage Payment Reference
For a $300,000 loan at 6.5% interest over 30 years, the monthly payment is approximately $1,896. Over 15 years, the same loan at the same rate costs about $2,613 per month but saves over $100,000 in total interest. A lower interest rate or shorter term both reduce your total cost significantly. Use this calculator to compare scenarios before committing to a loan.
Frequently Asked Questions
Does this include property tax and insurance?
No. This calculator computes the principal and interest portion of your mortgage payment only. Property tax, homeowner's insurance, and PMI (private mortgage insurance) are separate costs that vary by location and lender.
Is my data safe?
Yes. This tool runs entirely in your browser using JavaScript. No data is sent to any server. You can verify this by disconnecting from the internet — the calculator will still work.