Mortgage Calculator
Calculate mortgage payments instantly. See monthly payment, total interest, and amortization schedule for any home loan.
Last updated: June 2026
Example: $300,000 Mortgage at 6.5% for 30 Years
Inputs
Results
What This Means
→ This example shows a typical home purchase where a buyer finances $300,000 over 30 years at a 6.5% interest rate.
→ The monthly payment of $1,896.20 represents the principal + interest portion of the PITI (Principal, Interest, Taxes, Insurance) payment. Actual total monthly cost would include property taxes, homeowner's insurance, and possibly HOA fees.
→ Over 30 years, you'll pay a total of $682,632 — more than double the original loan amount. This $382,632 in interest is the cost of borrowing the money.
→ In the early years of the mortgage, most of your payment goes toward interest. After 20+ years, most goes toward principal. This is why paying extra on your principal early in the loan can save substantial interest.
Our calculators are built using established financial and scientific formulas. Finance tools follow standard amortization and compound interest principles. Health tools use WHO and NIH reference standards.
Last reviewed: June 2026
Learn more about our methodology →About the Mortgage Calculator
What Is a Mortgage Calculator and Why Does It Matter?
A mortgage calculator helps you estimate your monthly mortgage payment, total interest paid over the life of your loan, and how much of each payment goes toward principal versus interest. This tool is essential if you're buying a home, refinancing, or comparing different loan offers.
Understanding your monthly mortgage payment is critical because housing expenses typically consume 25–30% of your gross monthly income for most homeowners. By calculating your payment upfront, you can make an informed decision about how much house you can afford and whether a particular loan term works for your budget.
The Mortgage Amortization Formula
Our calculator uses the standard amortization formula, the same formula used by banks and lenders:
M = P × [r(1+r)^n] / [(1+r)^n - 1]
Where:
- M = Monthly mortgage payment
- P = Principal loan amount
- r = Monthly interest rate (annual rate ÷ 12)
- n = Total number of payments (years × 12)
For example, if you borrow $300,000 at 6.5% annual interest over 30 years, the monthly interest rate is 0.065 ÷ 12 = 0.00542, and the total number of payments is 30 × 12 = 360.
Understanding Your Results
When you get your mortgage calculation results, you'll see four key numbers:
Monthly Payment — The total amount you pay each month to your lender. This typically includes principal and interest, but may also include taxes and insurance (often called PITI).
Total Payment — The sum of all monthly payments over the life of the loan. For a 30-year mortgage, this is your monthly payment × 360. This number shows you the total cost of borrowing.
Total Interest — The difference between the total amount paid and your original loan amount. This represents the cost of borrowing money. A longer loan term means you'll pay more interest overall.
Principal Amount — Simply a reminder of how much you borrowed.
How Loan Term Affects Your Interest
Choosing between a 15-year, 20-year, or 30-year mortgage is one of the most important decisions. A 30-year mortgage has lower monthly payments but you'll pay significantly more interest. A 15-year mortgage costs more per month but you'll pay it off faster and save tens of thousands in interest.
For example, on a $300,000 loan at 6.5%:
- 30-year mortgage: $1,896/month, ~$182,512 in interest
- 15-year mortgage: $2,896/month, ~$20,328 in interest
The longer loan saves $1,000/month but costs over $160,000 extra in interest.
Interest Rate Benchmarks
Interest rates vary based on market conditions, credit score, down payment, and loan type. As of early 2024, typical mortgage rates range from 5.5–7.5% for conventional 30-year loans. Your actual rate depends on your creditworthiness and the current economic environment.
Even a 0.5% difference in your interest rate can mean tens of thousands of dollars over the life of the loan, so it's worth shopping around with multiple lenders.
The 28/36 Rule
Lenders typically want your housing payment (including taxes and insurance) to not exceed 28% of your gross monthly income. Some will go up to 36% of your total debt. Use this calculator's results along with these guidelines to determine if a mortgage amount fits your budget.
Frequently Asked Questions
A good mortgage interest rate depends on current market conditions, your credit score, down payment size, and loan type. As of 2024, rates typically range from 5.5–7.5% for conventional 30-year mortgages. Historically, rates below 6% are considered favorable. Your personal rate will be determined by your lender based on your financial profile. Shop with multiple lenders to find the best rate available to you.
How to Use This Calculator
- 1Enter the loan amount you plan to borrow (the price of the home minus your down payment).
- 2Enter the annual interest rate you've been offered or expect to receive. This varies by credit score and market conditions.
- 3Enter the loan term in years (15, 20, or 30 years are most common).
- 4Click "Calculate Mortgage" to see your monthly payment, total payment, and total interest.
- 5Review the results. If the monthly payment is more than 28% of your gross income, consider a larger down payment, longer term, or looking at a less expensive home.
- 6Use this calculator to compare different scenarios: try 15 years vs. 30 years, or compare interest rate offers from different lenders.