Calculator guide
Estimate a fixed-rate mortgage’s monthly principal-and-interest payment, then compare different loan amounts, interest rates, and repayment terms. This estimate is not a lender quote or the complete cost of home ownership.
Formula or method
M = P × r(1+r)^n / ((1+r)^n − 1), where P is principal, r is the monthly rate, and n is the number of payments.
How to use this calculator
- Enter the home price and down payment.
- Enter the annual interest rate and loan term.
- Review the payment and total interest; adjust an input to compare scenarios.
Worked example
A $300,000 loan at 6.5% for 30 years uses P=300000, r=0.065/12, and n=360, producing about $1,896.20 per month before taxes and insurance.
Understanding the result
Read the principal-and-interest payment separately from property taxes, homeowners insurance, mortgage insurance, association dues, maintenance, and closing costs. A longer term can reduce the monthly payment while increasing total interest. The schedule assumes an unchanged interest rate and regular payments.
Limitations and assumptions
- Assumes a constant rate and regular monthly payments.
- Does not predict lender approval, taxes, insurance, points, or closing costs.
Frequently asked questions
Does a down payment change interest?
Yes. A larger down payment reduces principal, which generally reduces the interest paid.
What if the rate is adjustable?
This estimate is not a forecast for an adjustable-rate loan; recalculate after any rate change.
Is this a lending quote?
No. Use it for education and ask a lender for a formal disclosure.
Sources
Educational estimate only; it is not financial advice or a loan offer.