Mortgage Payment Calculator
Enter your home price, down payment, interest rate, and loan term to calculate your monthly principal and interest payment, total interest paid, and key loan metrics.
How to Use This Calculator
Enter the home price, down payment (in dollars), annual interest rate, and loan term. The calculator shows your monthly principal and interest (P&I) payment — the core of your mortgage payment.
Note: Your full monthly housing payment will also include property taxes, homeowner's insurance, and possibly PMI and HOA fees. Add roughly 1.2–1.5% of the home value per year for taxes and insurance combined as a starting estimate.
Extra Payment Impact
Adding even a small extra payment each month can dramatically reduce the total interest paid and shorten the loan term. The calculator shows exactly how much you save and how many months early you would pay off the loan.
The Mortgage Payment Formula
The standard monthly payment formula for a fixed-rate mortgage is:
$$M = P \frac{r(1+r)^n}{(1+r)^n - 1}$$
Where:
- $M$ = monthly payment
- $P$ = principal (loan amount)
- $r$ = monthly interest rate (annual rate ÷ 12)
- $n$ = total number of payments (years × 12)
Understanding PMI
If your down payment is less than 20% of the home price, your LTV ratio exceeds 80% and most lenders require Private Mortgage Insurance (PMI). PMI typically costs 0.5–1.5% of the loan amount per year. Once your equity reaches 20% (LTV drops to 80%), you can usually request PMI cancellation.
Frequently Asked Questions
Does this include property taxes and insurance?
No — this calculator shows principal and interest only. A full PITI payment (Principal, Interest, Taxes, Insurance) adds your monthly escrow for property taxes and homeowner's insurance on top of this figure.
What's the difference between a 15-year and 30-year mortgage?
A 15-year mortgage has higher monthly payments but dramatically less total interest — often less than half the interest of a 30-year loan. A 30-year mortgage has lower monthly payments, giving more cash flow flexibility.
How does the interest rate affect my payment?
A 1% increase in rate on a $400,000 loan adds roughly $230–$250/month to the payment and tens of thousands in total interest over the life of the loan.
