Mortgage Payment Calculator

What this calculator does

This calculator estimates your monthly mortgage payment for a fixed-rate loan, based on the home price, down payment, interest rate, and loan term. The result is the principal-and-interest portion of your payment — what most people refer to as their “mortgage payment” — along with total interest paid over the life of the loan and a full month-by-month amortization schedule.

How the formula works

Fixed-rate mortgage payments use the standard amortization formula:

M = P × r(1+r)^n / ((1+r)^n − 1)

• P — loan principal (home price minus down payment)
• r — monthly interest rate (annual rate ÷ 12)
• n — total number of monthly payments (years × 12)

Each month, the bank charges interest on the remaining balance. Whatever is left of your payment after interest goes to principal, which reduces the balance for the next month. Early on, most of your payment is interest; near the end of the loan, most of it is principal.

A worked example

On a $320,000 loan at 6.5% for 30 years, the monthly payment is about $2,022. Total interest paid over the full term is roughly $408,000 — more than the loan itself. Adding an extra $200/month to principal cuts the term to about 25 years and saves more than $80,000 in interest.

Tips and common mistakes

• Don't confuse rate with APR. The interest rate drives the monthly payment; the APR includes fees and reflects the true annual cost.
• This is P&I, not PITI. Your real monthly housing cost will add property taxes, homeowners insurance, mortgage insurance (if applicable), and HOA dues.
• Apply extras to principal explicitly. Many lenders default extra payments to the next month's interest unless you specify “principal only.”
• Refinance math is its own calculator. Use a refinance break-even calculator to weigh closing costs against monthly savings.

Frequently asked questions

How is my monthly mortgage payment calculated?

The standard fixed-rate mortgage payment formula is M = P × r(1+r)^n / ((1+r)^n − 1), where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments (years × 12). This calculator uses that formula to compute principal and interest only — taxes, insurance, and HOA dues are not included.

What is principal vs interest?

Principal is the amount applied to your loan balance. Interest is what the lender charges for borrowing. Early in the loan, most of each payment goes to interest; later, more goes to principal.

Does this include property taxes and insurance?

No. The result is principal and interest (P&I) only. Your full PITI payment will include property taxes, homeowners insurance, and possibly mortgage insurance and HOA dues.

How much does an extra monthly payment save?

Extra payments go directly to principal, reducing the balance on which future interest is charged. On a 30-year loan, even $100–$200 extra per month can shorten the term by several years and save tens of thousands in interest.

What is the difference between a 15-year and 30-year mortgage?

A 15-year mortgage has higher monthly payments but a lower interest rate and far less total interest. A 30-year has lower monthly payments and is easier to qualify for, but you pay more total interest. Use a loan-comparison calculator to weigh both.

Is APR the same as the interest rate?

No. The interest rate is what the loan accrues. APR (annual percentage rate) includes the interest rate plus most fees and points, so it reflects the true annual cost of the loan.