15 V 30 Year Mortgage Calculator

Deciding between a 15-year and 30-year mortgage is a major financial decision that affects your monthly payments, total interest paid, and overall affordability. This calculator helps you compare the two options by showing monthly payments, total interest, and interest savings for each term.

How to Use This Calculator

Enter your home price, down payment, and interest rate to see how your monthly payments and total interest paid would differ between a 15-year and 30-year mortgage. The calculator shows:

Monthly payment for each term
Total interest paid over the loan term
Interest savings by choosing the 15-year term

Use the results to help decide which mortgage term is right for your financial situation.

15-Year vs 30-Year Mortgage Comparison

Here's a quick comparison of the key differences between 15-year and 30-year mortgages:

Feature	15-Year Mortgage	30-Year Mortgage
Loan term	15 years	30 years
Monthly payments	Higher (pay off loan faster)	Lower (spread payments over longer term)
Total interest paid	Lower (shorter term)	Higher (longer term)
Refinancing options	Less common	More common
Best for	Homeowners who want to pay off the loan quickly	Homeowners who want lower monthly payments

The table above summarizes the key differences between 15-year and 30-year mortgages. Use the calculator to see how these differences apply to your specific situation.

How the Calculation Works

The calculator uses the standard mortgage payment formula to calculate monthly payments and total interest paid for each term:

Monthly Payment Formula:

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

Where:

M = monthly payment
P = principal loan amount (home price - down payment)
i = monthly interest rate (annual rate / 12)
n = number of payments (loan term in years × 12)

The calculator then calculates the total interest paid by multiplying the monthly payment by the number of payments and subtracting the principal loan amount.

Worked Example

Let's look at an example to see how the calculations work. Suppose you're buying a home for $300,000 with a 20% down payment and a 5% interest rate.

Example Scenario:

Home price: $300,000
Down payment: 20% ($60,000)
Loan amount: $240,000
Interest rate: 5%

For a 15-year mortgage:

Monthly payment: $1,843.50
Total interest paid: $105,220
Total paid over 15 years: $345,220

For a 30-year mortgage:

Monthly payment: $1,230.60
Total interest paid: $204,780
Total paid over 30 years: $444,780

In this example, choosing the 15-year mortgage saves you $99,560 in interest over the life of the loan.

Frequently Asked Questions

Which mortgage term saves more money?: The 15-year mortgage typically saves more money in total interest paid, but the higher monthly payments may not be suitable for everyone.
Can I refinance a 15-year mortgage?: Refinancing a 15-year mortgage is less common than refinancing a 30-year mortgage, but it is possible with some lenders.
What's the minimum down payment for a 15-year mortgage?: Most lenders require at least 5% down payment for a 15-year mortgage, but some may allow as little as 3%.
Are there any penalties for paying off a 15-year mortgage early?: Yes, most 15-year mortgages have prepayment penalties that make it difficult to pay off the loan early.
Which mortgage term is better for my financial situation?: The best mortgage term depends on your financial goals, cash flow, and ability to handle higher monthly payments.