15-Year vs. 30-Year Mortgage: Which One is Right for You?

March 25, 2026·By Tucker Allen

The headline numbers

Take a $400,000 mortgage at 6.5% (30-year) vs. 6.0% (15-year — typically a touch lower because lenders carry less duration risk):

30-year: $2,528/month principal-and-interest. Total interest paid over the life of the loan: $510,178.
15-year: $3,375/month principal-and-interest. Total interest paid: $207,576.

That's about $850/month more for the 15-year, in exchange for $300,000 less in lifetime interest and being mortgage-free 15 years sooner.

The 30-year case

The 30-year keeps your monthly payment as low as possible. That matters when:

Your income is variable or you anticipate it growing.
You'd rather invest the difference in tax-advantaged accounts (401k, IRA, brokerage).
You want a buffer for life surprises — kids, job changes, medical events.
You don't expect to stay in the home long-term anyway, so total lifetime interest doesn't fully apply.

You can always pay extra principal voluntarily on a 30-year. Many borrowers take the 30-year for flexibility, then make the 15-year-equivalent payment when cash flow allows. No prepayment penalties on most modern mortgages.

The 15-year case

The 15-year wins on lifetime cost and time-to-payoff. That matters when:

You're in your peak earning years and want to be debt-free before retirement.
You have stable income and the higher payment fits comfortably.
You'd otherwise leave the savings in a checking account, not invest them.
You value the psychological win of seeing the balance drop fast.

The lower 15-year rate also helps. Most of the time, a 15-year loan prices about 0.25–0.5% below the 30-year — a meaningful difference compounded over the life of the loan.

The honest tradeoff

The math is straightforward, but the choice is partly behavioral. Mathematically, if you'll actually invest the monthly difference between the two payments at a return higher than your mortgage rate, the 30-year often wins. In practice, many people don't invest that difference — it gets spent.

If you take the 30-year and spend the difference, you've effectively chosen the higher-cost path with none of the discipline. If you take the 15-year, the discipline is built in.