15 vs 30 Year Mortgage Calculator

What is a 15 vs 30 year mortgage calculator?

A 15 vs 30 year mortgage calculator compares the estimated monthly principal-and-interest payments and total interest for two loan terms. You enter a loan amount and the interest rate for each term. The calculator uses the standard mortgage payment formula for each loan.

A 15-year mortgage has a shorter repayment period, so its monthly payment is usually higher than a 30-year mortgage payment for the same loan amount. But the shorter term generally means paying interest for less time. Your actual comparison also depends on the rates you enter, which may differ between the loans.

Why compare 15-year and 30-year mortgages?

The payment affects how much room you have in your monthly budget for housing costs, savings, and other expenses. A lower payment may leave more cash available for repairs or financial goals. A higher payment may reduce the time you spend paying interest, but it can leave less flexibility if your income changes.

Comparing total interest shows the long-term cost of each option based on your inputs. Use that estimate alongside the monthly payment when deciding how much house to buy, whether to put more money toward the mortgage, or whether a shorter term is worth the tighter budget.

The result is an estimate of principal and interest, not your full housing cost. Property taxes, homeowners insurance, mortgage insurance, homeowners association dues, and loan fees can add to what you pay. Check your lender’s loan estimate and budget for those costs before choosing a loan.

How to use this 15 vs 30 year mortgage calculator

1. Enter the amount you plan to borrow. Use the loan balance you expect to finance, not the home’s purchase price if you will make a down payment.
2. Enter the interest rate for the 15-year loan, then enter the rate for the 30-year loan. Use the rates offered for the terms you are comparing when available.
3. Review the estimated monthly payment for each loan and the difference between them. Consider whether the higher payment fits comfortably alongside your other housing costs.
4. Compare total interest and the estimated interest saved with the shorter term. Remember that the savings reflect both the loan term and the rates entered.
5. Change the loan amount or rates to test other choices, such as borrowing less or comparing different lender offers. For a broader housing budget, pair this result with a mortgage calculator that includes taxes and insurance.

15-year vs 30-year mortgage example

How to read your mortgage comparison

The monthly payment rows estimate the amount applied to principal and interest. The difference per month tells you how much more the shorter-term payment would cost under the rates you entered. Compare that amount with your take-home budget after accounting for other housing expenses.

Total interest estimates the interest paid over the full loan term if you make the scheduled payments and the rate stays as entered. Interest saved is the difference between the two total-interest estimates. It is not a promise of savings if you later refinance, make extra payments, miss payments, or have a loan with changing terms.

How to make the mortgage choice work better for you

1. 01

   Compare real offers

   Ask lenders for quotes on both terms and enter each quoted rate. Compare loan fees and other costs separately, since this calculator does not include them. A lower rate or lower fees can change which offer costs less overall.

2. 02

   Test a smaller loan amount

   Consider whether a larger down payment, a less expensive home, or paying down other debt before buying could make the monthly payment more manageable. Recalculate with the amount you would actually borrow.

3. 03

   Protect your monthly flexibility

   Before choosing the shorter term, check whether the payment still leaves room for routine expenses, home repairs, and savings. If the payment would strain your budget, compare the longer term rather than relying on an optimistic income or spending assumption.

4. 04

   Review the decision over time

   If your finances change, revisit your mortgage options and ask your lender about the costs and terms of refinancing or making extra principal payments. Compare any new costs with the interest you expect to avoid.

Common 15-year vs 30-year mortgage mistakes

• Treating the payment as the full housing bill

  The estimate covers principal and interest. Add property taxes, insurance, mortgage insurance, and other housing expenses to judge affordability.

• Comparing different rates as if term were the only change

  The two loan rates can differ. In the example, the 15-year rate is 5.75% and the 30-year rate is 6.5%. The resulting interest difference is due to both the term and the rates.

• Choosing only by total interest

  A lower total-interest estimate can come with a higher required payment. Consider both the long-term cost and the cash you need to keep available for everyday needs and unexpected expenses.

• Assuming the estimate includes future changes

  The calculation applies the standard formula to the entered loan amount, term, and rate. It does not account for refinancing, extra payments, or changes in loan terms.

The 15 vs 30 year formula

Key terms

Principal

The amount borrowed for the home, before interest and other loan costs.

Interest

The cost charged for borrowing money. Total interest is the estimated interest paid over the loan term.

Loan term

The period used to repay the mortgage. This calculator compares 15-year and 30-year terms.

Monthly payment

The estimated scheduled payment for principal and interest. It does not include other housing costs.