15-Year vs 30-Year Mortgage: The Real Trade-Off

Published 2026 ? 4 min read

The 15-year mortgage has a much lower rate and pays off half as fast ? so why does anyone choose 30? Because the 30-year frees cash that can be invested, and the gap is wider than most people think.

The two numbers that matter

• 15-year: lower rate, higher payment, dramatically less interest, home paid off in half the time.
• 30-year: lower payment, higher rate, far more interest ? but the payment difference can be invested.

The honest comparison

Take the difference between the two payments and invest it monthly at a reasonable return. Over 15 years, the invested difference often beats the interest saved ? which flips the "obvious" choice.

When 15 wins

You want the forced discipline of a higher payment, you're conservative with investing, or you value being mortgage-free before retirement.

When 30 wins

You'll invest the difference, your income is variable, or you'd rather keep the flexibility of a lower mandatory payment.

Run the numbers

Use the mortgage calculator to compare the payments at each term, then the compound interest calculator to see what the difference could grow into.