15 Year vs 30 Year Mortgage Payment Calculator

When buying a home, one of the biggest financial decisions you'll make is choosing between a 15-year and 30-year mortgage. This calculator helps you compare the two options by showing how loan term affects your monthly payments, total interest paid, and potential savings.

How the Calculator Works

The mortgage payment calculator uses the standard mortgage payment formula to determine your monthly payments for both loan terms:

Monthly Payment Formula:

M = P [ i(1 + i)ⁿ ] / [ (1 + i)ⁿ - 1 ]

Where:

M = Monthly payment
P = Principal loan amount
i = Monthly interest rate (annual rate divided by 12)
n = Number of payments (loan term in years × 12)

The calculator compares:

Monthly payments for both loan terms
Total interest paid over the life of the loan
Total amount paid (principal + interest)

Key assumptions:

Fixed interest rate
No prepayment penalties
No additional costs (closing costs, taxes, insurance)

15-Year vs 30-Year Comparison

Here's what you need to know about the two mortgage terms:

15-Year Mortgage

Higher monthly payments than a 30-year mortgage
Lower total interest paid over the life of the loan
Faster payoff, which can save you money on interest
May qualify for lower interest rates
Requires more discipline to avoid refinancing

30-Year Mortgage

Lower monthly payments than a 15-year mortgage
Higher total interest paid over the life of the loan
More flexible payment schedule
May qualify for higher interest rates
Longer payoff period

Pro Tip: A 15-year mortgage can save you thousands in interest payments, but the higher monthly payments may be difficult to manage if you have other financial obligations.

Worked Example

Let's compare a $200,000 mortgage with a 4% interest rate:

Term	Monthly Payment	Total Interest	Total Paid
15 Years	$1,524.35	$108,354	$308,354
30 Years	$1,013.86	$188,238	$388,238

In this example, choosing a 15-year mortgage saves you $80,000 in interest payments over the life of the loan, but requires higher monthly payments.

Frequently Asked Questions

Which mortgage term is better?

The better term depends on your financial situation. A 15-year mortgage can save you money on interest but requires higher monthly payments. A 30-year mortgage has lower monthly payments but higher total interest costs.

Can I refinance a 15-year mortgage to a 30-year?

Yes, you can refinance a 15-year mortgage to a 30-year mortgage, but you may pay additional fees and lose some of the interest savings.

What factors affect mortgage interest rates?

Interest rates are influenced by the federal funds rate, inflation, economic conditions, and the borrower's credit score and loan type.