15 vs 30 Year Mortgage: Which Saves More?

The same loan, two terms — and a six-figure difference in interest.

By Michael Bennett, Personal Finance & Tax Writer · Updated June 2026

A 15-year mortgage saves you a fortune in interest and a lower rate, but the monthly payment is much higher. A 30-year mortgage keeps payments low and flexible, but you pay far more interest over time. On a $400,000 loan, the choice can swing your total interest by more than $300,000 — so it is worth getting right.

Open the Mortgage Calculator — try 15 vs 30 yr →

Quick verdict

Choose a 15-year mortgage if you can comfortably afford the higher payment and want to be debt-free sooner with minimal interest. Choose a 30-year mortgage if you value lower payments, cash-flow flexibility, or plan to invest the difference. Many buyers split the difference: take the 30-year for safety and make extra principal payments when they can.

15 vs 30 year mortgage at a glance

Example: a $400,000 loan at illustrative 2026 rates — 6.5% for the 30-year, 5.75% for the 15-year (15-year loans almost always carry a lower rate).

Feature15-year30-year
Example interest rate5.75%6.50%
Monthly payment (P&I)~$3,320~$2,530
Total interest paid~$198,000~$510,000
Total of payments~$598,000~$910,000
Years to debt-free1530
Equity built faster✅ Yes❌ Slower
Payment flexibility❌ Locked high✅ Lower & flexible
Room to invest the difference❌ Less✅ ~$790/mo freed up

Rates are illustrative as of 2026 and vary by lender, credit score and down payment. Run your own figures with the Mortgage Calculator.

The case for a 15-year mortgage

The case for a 30-year mortgage

A worked example

On the $400,000 loan, the 15-year borrower pays roughly $3,320 a month and hands the bank about $198,000 in interest. The 30-year borrower pays about $2,530 a month but roughly $510,000 in interest over the full term. The 30-year frees up about $790 a month — invested consistently at a strong return, that gap can partly close, but only if you actually invest it rather than spend it.

Plug your real loan amount, rate and down payment into the Mortgage Calculator to see your exact payment and amortization schedule, or use the Loan Calculator to compare any two terms side by side.

Which should you choose?

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Frequently asked questions

Is a 15 or 30 year mortgage better?

A 15-year mortgage is better if your goal is to pay the least interest and own your home sooner — it typically saves hundreds of thousands in interest and comes with a lower rate. A 30-year mortgage is better if you want lower, more flexible monthly payments and the freedom to invest the difference. It depends on your cash flow and goals.

How much more is a 15 year mortgage per month?

On a $400,000 loan, a 15-year mortgage runs roughly $790 a month more than a 30-year — about $3,320 versus $2,530 in our 2026 example. The exact gap depends on the rates you are offered.

Can I pay off a 30 year mortgage early instead?

Yes. A 30-year loan with extra principal payments gives you flexibility — pay it down like a 15-year loan in good months and drop back to the lower payment when needed. The trade-off is that 30-year rates are usually higher.

Why is the interest so much higher on a 30 year mortgage?

You borrow for twice as long and at a higher rate, so a 30-year mortgage can cost more than double the total interest of a 15-year mortgage on the same loan amount.