Mortgage Calculator
Estimate your monthly mortgage payment, total interest, and see how principal and interest break down over the life of the loan.
$
$ 20%
%
Monthly Payment (P&I)
$2,022
Loan amount: $320,000
TOTAL COST BREAKDOWN
Principal Interest
How to Use the Mortgage Calculator
Enter the home price, your down payment, the interest rate, and the loan term. The calculator instantly shows your estimated monthly principal and interest payment, the total amount you'll pay over the life of the loan, and the total interest cost. The bar chart visualizes how much of your total cost goes to principal versus interest.
The Mortgage Payment Formula
M = P × [ r(1 + r)ⁿ ] ÷ [ (1 + r)ⁿ − 1 ]
M = monthly payment
P = loan principal (price − down payment)
r = monthly interest rate (annual rate ÷ 12)
n = total number of payments (years × 12)
M = monthly payment
P = loan principal (price − down payment)
r = monthly interest rate (annual rate ÷ 12)
n = total number of payments (years × 12)
Example Calculation
For a $400,000 home with a $80,000 down payment (20%) at 6.5% for 30 years:
- Loan principal: $400,000 − $80,000 = $320,000
- Monthly rate: 6.5% ÷ 12 = 0.5417%
- Number of payments: 30 × 12 = 360
- Monthly payment: $2,022
- Total paid over 30 years: about $728,000, of which roughly $408,000 is interest
Monthly Payment by Loan Term
On a $320,000 loan at 6.5% interest:
| Term | Monthly Payment | Total Interest |
|---|---|---|
| 30 years | $2,022 | $408,000 |
| 20 years | $2,386 | $252,600 |
| 15 years | $2,788 | $181,800 |
| 10 years | $3,634 | $116,100 |
Disclaimer: Estimates are for informational purposes only and do not include taxes, insurance, or PMI. This is not financial advice. Consult a licensed mortgage professional.
Frequently Asked Questions
How is a monthly mortgage payment calculated?
The monthly payment uses the amortization formula: 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).
What is included in a mortgage payment?
This calculator shows principal and interest (P&I). A full monthly housing payment often also includes property taxes, homeowner's insurance, and possibly PMI (private mortgage insurance) if your down payment is under 20%.
How much interest will I pay over the life of the loan?
Total interest depends on the loan amount, rate, and term. On a $300,000 loan at 6.5% for 30 years, you'd pay roughly $382,000 in interest. Shorter terms and lower rates dramatically reduce total interest.
Is a 15-year or 30-year mortgage better?
A 15-year mortgage has higher monthly payments but far less total interest and builds equity faster. A 30-year mortgage has lower monthly payments and more flexibility. Choose based on your budget and financial goals.
How does the interest rate affect my payment?
Even a small rate change matters. On a $300,000 30-year loan, each 1% rate increase adds roughly $190–$200 to the monthly payment and tens of thousands in total interest.
What is PMI?
Private Mortgage Insurance is typically required when your down payment is below 20% of the home price. It usually costs 0.5%–1% of the loan amount per year and is added to your monthly payment until you reach 20% equity.
Is this calculator financial advice?
No. This tool provides estimates for informational purposes only. Actual loan terms vary by lender. Consult a licensed mortgage professional or financial advisor before making decisions.