This mortgage calculator estimates your monthly payment using the standard amortization formula used by banks and lenders worldwide. Enter your loan amount, the annual interest rate offered by your lender, and your loan term in years to get an instant estimate of your fixed monthly payment.
Monthly payments are calculated using the standard amortization formula: M = P × r(1+r)^n / ((1+r)^n − 1)
Where P is the principal loan amount, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments (years multiplied by 12). The result is your fixed monthly principal and interest payment.
Suppose you're buying a home and taking out a $300,000 mortgage at a 6.5% annual interest rate over a 30-year term.
First, convert the annual rate to a monthly rate: 6.5% ÷ 12 = 0.5417% per month (or 0.005417). The total number of payments is 30 × 12 = 360.
Plugging into the formula gives a monthly payment of approximately $1,896.20. Over the full 30 years, you'd pay around $382,633 in interest on top of the $300,000 principal — a total of roughly $682,633. This illustrates why even a small reduction in interest rate or a larger down payment can save tens of thousands of dollars over the life of a loan.
Three main factors determine your monthly payment: the loan amount (principal), the annual interest rate, and the loan term. A larger loan, higher rate, or shorter term all increase your monthly payment. Conversely, a smaller loan, lower rate, or longer term reduce it. Your down payment directly affects the loan amount — a 20% down payment on a $400,000 home means you only finance $320,000.
No. This calculator estimates principal and interest only. Your actual monthly housing cost will typically also include property taxes, homeowners insurance, and — if your down payment is less than 20% — private mortgage insurance (PMI). These costs vary significantly by location and lender, so consult your lender for a full payment estimate including escrow.
Mortgage rates fluctuate based on economic conditions, Federal Reserve policy, and your personal credit profile. Generally, borrowers with higher credit scores (720+) qualify for the best available rates. It's worth comparing offers from multiple lenders — even a 0.25% difference in rate can save thousands of dollars over a 30-year mortgage.
There are several strategies: increase your down payment to reduce the loan principal; choose a longer loan term (e.g., 30 years instead of 15) to spread payments out; improve your credit score before applying to qualify for a better rate; or shop around with multiple lenders to find the most competitive offer. Keep in mind that a longer term means more total interest paid over the life of the loan, even if monthly payments are lower.
A 15-year mortgage has higher monthly payments but significantly less total interest paid — you pay off the loan in half the time and typically qualify for a lower interest rate. A 30-year mortgage has lower monthly payments, giving you more cash flow flexibility, but you'll pay considerably more in interest over the life of the loan. Use this calculator to compare both scenarios by changing the loan term field.
This calculator uses the same standard amortization formula used by banks and mortgage lenders. The estimate is accurate for fixed-rate mortgages. Adjustable-rate mortgages (ARMs) will vary after the initial fixed period. The calculator does not account for taxes, insurance, HOA fees, or other costs. For a full picture, speak with a licensed mortgage lender or financial advisor.