Mortgage Calculator
Estimate a monthly house payment using home price, down payment, interest rate, loan term, property tax, and insurance. This is a planning calculator for comparing scenarios before speaking with a lender.
How the mortgage payment is calculated
The principal and interest portion uses the standard fixed-rate amortization formula. Property tax and insurance are then added as monthly estimates.
M = P × [r(1 + r)^n] / [(1 + r)^n - 1]
In this formula, M is the monthly principal and interest payment, P is the loan amount, r is the monthly interest rate, and n is the number of monthly payments.
Example
For a $420,000 home with $84,000 down, the loan amount is $336,000. At 6.5% for 30 years, principal and interest are estimated first, then monthly tax and insurance are added to show a broader monthly housing estimate.
What is not included
- Private mortgage insurance, commonly called PMI.
- HOA dues, condo fees, lender fees, or closing costs.
- Escrow changes, rate locks, points, or adjustable-rate changes.
FAQ
Is this a lender quote?
No. It is an estimate for planning and comparison. A lender quote can include fees, underwriting rules, credit factors, and local costs.
Why does the down payment matter?
A larger down payment lowers the loan amount, which usually lowers the monthly principal and interest payment.
Does this include taxes and insurance?
Yes, if you enter annual tax and insurance estimates. They are divided by 12 and added to the monthly estimate.