15 Year Fixed vs 30 Year Fixed Mortgage Calculator

When choosing between a 15-year fixed and 30-year fixed mortgage, you're making one of the most important financial decisions of your life. Our calculator helps you compare the two options by showing you the monthly payments, total interest paid, and how much you'll save over the life of the loan.

How the Calculator Works

The mortgage calculator uses standard financial formulas to compare 15-year and 30-year fixed mortgages. The key inputs are:

Home price
Down payment percentage
Interest rate

The calculator then calculates:

Loan amount for each term
Monthly payment for each term
Total interest paid over the life of the loan
Total amount paid (principal + interest)

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 / 12)
n = Number of payments (term in years × 12)

The calculator uses this formula for both 15-year and 30-year terms, adjusting the number of payments accordingly.

Key Differences Between 15-Year and 30-Year Fixed Mortgages

The main differences between these two mortgage terms are:

Term length: 15 years vs 30 years
Monthly payments: Higher for 15-year loans due to shorter repayment period
Interest costs: Generally lower for 30-year loans
Refinancing options: Easier to refinance 30-year loans
Cash flow impact: 15-year loans require larger monthly payments

Important Note

While 15-year fixed mortgages have higher monthly payments, they can be a good option if you plan to sell or refinance within 15 years, or if you want to pay off your mortgage faster.

Pros and Cons of Each Term

15-Year Fixed Mortgage

Pros:

Lower total interest payments over the life of the loan
Faster payoff, which can save you money on interest
Potential tax benefits if you itemize deductions
More predictable payments

Cons:

Higher monthly payments
Less time to build equity
May not qualify for certain mortgage programs
Stricter underwriting requirements

30-Year Fixed Mortgage

Pros:

Lower monthly payments
More time to build equity
Wider eligibility for mortgage programs
More flexible refinancing options

Cons:

Higher total interest payments
Longer repayment period
Interest rate changes could affect payments

Example Comparison

Let's look at an example with a $300,000 home price, 20% down payment, and 6% interest rate:

Term	Loan Amount	Monthly Payment	Total Interest	Total Amount Paid
15-Year Fixed	$240,000	$2,125	$126,320	$366,320
30-Year Fixed	$240,000	$1,443	$211,360	$451,360

In this example, the 15-year fixed mortgage has lower total interest payments but higher monthly payments. The 30-year fixed mortgage has lower monthly payments but higher total interest costs.

Frequently Asked Questions

Which mortgage term is better for me?

The best mortgage term depends on your financial situation and goals. If you want to pay off your mortgage faster and can handle higher monthly payments, a 15-year fixed mortgage might be better. If you prefer lower monthly payments and can afford the longer repayment period, a 30-year fixed mortgage may be more suitable.

Can I refinance a 15-year fixed mortgage?

Yes, you can refinance a 15-year fixed mortgage, but it may be more difficult to qualify for a lower interest rate than with a 30-year mortgage. Many lenders prefer 30-year mortgages for refinancing.

Are there any tax benefits to a 15-year fixed mortgage?

Yes, if you itemize your deductions, you may be able to deduct the interest paid on your mortgage. Since 15-year mortgages have lower total interest payments, this could result in tax savings.

What happens if interest rates rise after I get a 15-year fixed mortgage?

Since 15-year fixed mortgages have a fixed interest rate for the entire term, your monthly payments will not change if interest rates rise. This provides stability in your budget.