About the Mortgage Calculator
This free online mortgage calculator helps you estimate your monthly mortgage payment, total interest paid, and overall loan cost based on the home price, down payment, interest rate, and loan term. Whether you’re a first-time homebuyer comparing a 30-year fixed-rate mortgage to a shorter 15-year option, or a homeowner evaluating a refinance, this tool provides fast, transparent, and accurate calculations to support smarter decisions.
Use the calculator to test different down payments, interest rates, and amortization periods to see how they affect monthly payments and long-term interest costs. You can also explore how a rate buydown, improved credit score, or larger down payment may change affordability. While results focus on principal and interest, remember to account for property taxes, homeowners insurance, HOA dues, and potential PMI when building your total housing budget.
Mortgage payments are amortized—early payments are interest-heavy, with principal reduction accelerating over time. Understanding this amortization structure helps you decide whether making extra payments, refinancing, or choosing a shorter term aligns best with your financial goals. Experiment freely to optimize for cash flow, total cost, or time to own your home free and clear.
How to use
- Enter the home price and down payment.
- Select a loan term (15–30 years are common).
- Provide an annual interest rate.
- View your monthly payment, loan amount, total interest, and total payment.
Formula
Monthly Payment = P × [ r(1 + r)n ] / [ (1 + r)n − 1 ]
Variables
| Symbol | Meaning |
|---|---|
| P | Loan amount (home price − down payment) |
| r | Monthly interest rate (annual rate ÷ 12 ÷ 100) |
| n | Total payments (years × 12) |
Examples
- Loan $240,000 at 6.5% for 30 years: payment ≈ $1,517 (principal & interest only).
- Increasing a down payment from 10% to 20% can remove PMI and reduce both payment and total interest.
- Choosing a 15-year term raises the monthly payment but can save tens of thousands in interest.
- Making one extra principal payment per year may shave years off the mortgage term.
Tips
- Keep your debt-to-income (DTI) ratio within lender guidelines to improve approval odds.
- Compare APRs, not just interest rates—APR reflects certain fees and gives a more apples-to-apples comparison.
- Locking your mortgage rate can protect you from market moves during underwriting.
- Ask lenders about points: paying points increases upfront costs but may reduce your rate and monthly payment.
- Build an emergency fund; homeownership includes ongoing maintenance and unexpected repairs.