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.

Some buyers compromise with a 30-year loan plus voluntary extra payments, which keeps the required payment low for flexibility while letting you pay it off like a 15-year term when cash allows. This hybrid gives you the best of both: the security of a smaller obligation during tight months and the option to save years of interest whenever you can pay ahead - no lender approval or refinance needed.