15- vs. 30-Year Mortgage: Which Should You Choose?
The choice between a 15- and 30-year mortgage comes down to one trade-off: a lower monthly payment versus far less interest paid over time. Both are valid — the right answer depends on your budget, your goals, and your discipline.
The core trade-off
Take a $320,000 loan. At typical rates (15-year loans usually carry a slightly lower rate than 30-year), the difference is stark:
| 30-year @ 6.5% | 15-year @ 5.75% | |
|---|---|---|
| Monthly payment (P&I) | ≈ $2,023 | ≈ $2,658 |
| Total interest | ≈ $408,000 | ≈ $158,000 |
The 15-year payment is about $635 higher each month, but it saves roughly $250,000 in interest and gets you mortgage-free in half the time. That's the whole debate in one table.
Compare your own loan both ways with the mortgage calculator, and see the interest breakdown in the amortization calculator.
When a 15-year makes sense
Choose the 15-year if the higher payment fits comfortably within the 28/36 affordability guideline (check the affordability guide), you value being debt-free sooner — especially before retirement — and you'd otherwise be tempted to spend rather than invest the difference. The forced discipline and interest savings are real advantages.
When a 30-year makes sense
Choose the 30-year if the lower payment gives you breathing room for other goals: building an emergency fund, capturing a 401(k) match, or simply not living on the edge. The flexibility matters — a lower required payment is easier to sustain through a job loss or emergency than a high one.
The middle path most people miss
You don't have to choose all-or-nothing. A popular strategy: take the 30-year loan but pay it like a 15-year when you can. Because a 30-year has a lower required payment, you keep the flexibility to drop back to it in a tight month — but by making extra principal payments in good months, you can approach 15-year savings on your own terms.
Adding about $635/month to the 30-year payment above replicates the 15-year payoff timeline — but you're never obligated to.
The catch is discipline: the money only works if you actually send it to principal (labeled "principal-only") rather than spending it. Model the effect with the mortgage payoff calculator.
One more factor: opportunity cost
If your mortgage rate is low, the math for investing the payment difference (rather than paying down the loan) can favor investing — historically, diversified stock returns have exceeded typical mortgage rates over long periods. If your rate is high, guaranteed interest savings from paying down look better. There's no universally right answer, which is exactly why the flexible 30-year approach appeals to so many buyers: it lets you decide year by year.
General educational information, not financial advice. Rates and your situation vary; run your own numbers. Last reviewed: July 2026.