15-Year vs 30-Year Mortgage: Which Is Right for You?

The numbers side by side

Let's compare the same $300,000 loan at 7% on both terms. The 30-year gives you a lower monthly payment but costs far more over the life of the loan.

• 30-year at 7%: $1,996/month, total interest $418,607, total paid $718,607 over 30 years.
• 15-year at 7%: $2,696/month, total interest $185,337, total paid $485,337 over 15 years.
• Difference: $700/month more on the 15-year, but $233,270 less in total interest. You pay the loan off in half the time.
• 15-year rates are typically 0.25–0.5% lower than 30-year rates. At 6.75% for the 15-year, the payment drops to $2,653 and total interest to $177,440 — even better.

The investment argument for the 30-year

The case for the 30-year is: take the lower payment and invest the $700/month difference. If you can earn 7% consistently for 30 years, $700/month grows to $846,000. Compare that to the $233,270 in interest saved on the 15-year — the 30-year plus investing comes out ahead by $612,000.

But this argument has three problems. First, 7% for 30 years is not guaranteed — the market has decades-long periods of lower returns. Second, it requires discipline: you must actually invest the $700 every month, not spend it. Third, the 15-year mortgage is a guaranteed 7% return (every dollar of principal saves 7% of interest), while the market return is uncertain.

The ROI calculator can show you what $700/month at various return rates would grow to — but remember that historical returns don't guarantee future ones.

The security argument for the 15-year

The 15-year mortgage has a hidden advantage: in 15 years, you own your home free and clear. No mortgage payment at all. That's $1,996/month (or whatever your payment was) that stays in your pocket — for the next 15 years of the 30-year comparison period.

From year 16 to 30, the 15-year homeowner pays $0/month. The 30-year homeowner still pays $1,996/month. If the 15-year homeowner invests that $1,996/month from year 16–30 at 7%, it grows to about $847,000. Meanwhile, the 30-year homeowner who was investing $700/month for 30 years has about $846,000.

The numbers are remarkably close — which means the real question isn't which earns more, but which fits your life. Do you want a lower payment now (30-year) or a paid-off home sooner (15-year)?

The middle path: 30-year with extra payments

A common strategy: take the 30-year for the lower required payment, then make extra principal payments as if it were a 15-year. You get the safety of a low minimum payment (if you lose your job, you only owe $1,996, not $2,696) and the interest savings of a shorter term.

On a $300,000/7%/30-year loan, paying an extra $700/month ($2,696 total) pays off the loan in about 15.5 years and saves roughly $225,000 in interest — nearly the same as the 15-year. But if your income drops, you can revert to the $1,996 minimum payment.

This flexibility is why many financial advisors recommend the 30-year plus extra payments over the 15-year. You get the interest savings without the obligation. The only cost: 15-year loans typically have slightly lower rates (0.25–0.5%), so you pay a small rate premium for the flexibility.

When the 15-year makes sense

The 15-year makes sense when: you're confident in your income stability, you're older and want the home paid off before retirement, you value the forced savings of the higher payment, and the higher payment doesn't squeeze your other financial goals.

It's especially powerful in retirement planning. If you're 45 and take a 15-year mortgage, your home is paid off at 60 — just before typical retirement age. That dramatically reduces your retirement living costs.

Use the home affordability calculator to see what home price you can afford on a 15-year payment, since you'll qualify for less house (the higher payment means a lower max loan).

When the 30-year makes sense

The 30-year makes sense when: you're early in your career and your income is growing, you want to max out retirement contributions (the lower payment frees cash for 401(k)/IRA), you're in a high-tax state where the mortgage interest deduction is valuable, or you might move within 10 years.

For most first-time buyers, the 30-year is the safer choice. The lower payment gives flexibility to handle job changes, children, and unexpected expenses. You can always make extra payments — but you can't reduce your required payment if money gets tight (without refinancing).