15-Year Mortgage Rate Calculator

Use this 15-year mortgage rate calculator to estimate your monthly payments and total interest costs for a 15-year mortgage. Simply enter your loan amount, interest rate, and down payment to get an accurate calculation.

How to Use This Calculator

To calculate your 15-year mortgage payments:

Enter the total loan amount you're borrowing
Input the current interest rate (annual percentage)
Specify your down payment amount (if any)
Click "Calculate" to see your monthly payment and total interest

The calculator will show you both the monthly payment amount and the total interest paid over the life of the loan. You can also view a breakdown of your payments over time in the chart below the results.

Formula Used

The calculator uses the standard mortgage payment formula:

Monthly Payment Formula

P = L × [r(1 + r)^n] / [(1 + r)^n - 1]

Where:

P = Monthly payment
L = Loan amount (principal)
r = Monthly interest rate (annual rate ÷ 12 ÷ 100)
n = Number of payments (loan term in years × 12)

For a 15-year mortgage, n = 15 × 12 = 180 payments. The total interest paid is calculated by multiplying the monthly payment by 180 and subtracting the original loan amount.

Worked Example

Let's calculate a 15-year mortgage with these parameters:

Loan amount: $200,000
Interest rate: 4.5%
Down payment: $40,000

First, calculate the principal amount: $200,000 - $40,000 = $160,000

Monthly interest rate: 4.5% ÷ 12 ÷ 100 = 0.00375

Number of payments: 15 × 12 = 180

Using the formula:

Calculation Steps

P = 160,000 × [0.00375(1 + 0.00375)^180] / [(1 + 0.00375)^180 - 1]

P ≈ $1,075.64 per month

Total payments = 180 × $1,075.64 = $193,615.20

Total interest = $193,615.20 - $160,000 = $33,615.20

This example shows that with a $160,000 loan at 4.5% interest, your monthly payment would be approximately $1,075.64, with $33,615.20 paid in interest over 15 years.

Frequently Asked Questions

What is a 15-year mortgage?

A 15-year mortgage is a home loan that's repaid over 15 years (180 months) instead of the more common 30-year term. This typically results in lower monthly payments but higher total interest costs compared to a 30-year mortgage.

How does the interest rate affect my payments?

A higher interest rate means you'll pay more in interest over the life of the loan, which increases your total repayment amount. The calculator shows both the monthly payment and total interest paid for any given interest rate.

What is the difference between APR and interest rate?

APR (Annual Percentage Rate) includes all fees and costs associated with borrowing, while the interest rate is the actual cost of borrowing. The APR is typically higher than the interest rate because it includes additional costs.

Can I refinance to a 15-year mortgage later?

Yes, many homeowners refinance to a 15-year mortgage after several years of a 30-year loan to take advantage of lower interest rates and pay off their mortgage faster. This can save thousands in interest payments.