15-Year vs. 30-Year Mortgage: Which Is Right for You?
The choice between a 15-year and 30-year mortgage is one of the most consequential decisions you'll make when buying a home. It affects your monthly cash flow, how quickly you build equity, how much interest you pay over the life of the loan, and ultimately your long-term financial flexibility.
There's no universally correct answer — it depends on your income stability, other financial goals, and how long you plan to stay in the home. Here's what the numbers actually look like and how to decide which is right for your situation.
The Numbers Side by Side
Let's compare both options on a $320,000 loan (after a 20% down payment on a $400,000 home) using current approximate rates:
| Metric | 30-Year @ 6.75% | 15-Year @ 6.25% |
|---|---|---|
| Monthly Payment (P&I) | $2,076 | $2,744 |
| Monthly Difference | — | +$668 more |
| Total Interest Paid | $427,360 | $173,920 |
| Total Amount Paid | $747,360 | $493,920 |
| Interest Savings | — | $253,440 saved |
| Equity at Year 5 | ~$37,000 | ~$82,000 |
| Equity at Year 10 | ~$60,000 | ~$186,000 |
The 15-year mortgage saves over $253,000 in interest — but requires $668 more per month. Over 15 years, that's $120,240 in additional payments. The question is whether the $253,000 in interest savings justifies the higher required cash outlay each month.
Pros and Cons of Each
✅ 15-Year Mortgage
- Lower interest rate (typically 0.5–0.75% less)
- Builds equity much faster
- Saves hundreds of thousands in interest
- Paid off in half the time
- Forced savings discipline
- Better for those near retirement
✅ 30-Year Mortgage
- Lower required monthly payment
- More cash flow flexibility
- Easier to qualify for a larger loan
- Extra cash can be invested elsewhere
- Lower stress if income fluctuates
- Can always pay extra principal voluntarily
The "Invest the Difference" Argument
One popular argument for the 30-year mortgage goes like this: take the $668/month you'd save vs. the 15-year payment and invest it in the stock market instead. Historically, the S&P 500 has returned an average of about 10% annually. Over 15 years, investing $668/month at 8% average returns would grow to approximately $230,000.
On paper, this almost offsets the $253,000 in interest savings from the 15-year loan. So the math is closer than most people realize — especially if you're a disciplined investor.
💡 The catch: Most people don't actually invest the difference. They spend it. If you're not confident you'll invest that extra $668 every single month for 15 years, the 15-year mortgage acts as forced savings and is almost certainly the better financial choice.
When the 15-Year Mortgage Makes More Sense
- You have stable, reliable income and the higher payment is genuinely comfortable
- You're in your 40s or 50s and want to be mortgage-free before retirement
- You're a disciplined spender but not necessarily a disciplined investor
- You want to maximize home equity quickly (useful if you plan to use equity for a future purchase)
- You're buying a modest home and the payment difference is manageable
When the 30-Year Mortgage Makes More Sense
- The higher 15-year payment would stretch your budget uncomfortably
- You have other high-interest debt to pay off first
- You're early in your career with income likely to grow significantly
- You plan to move within 7–10 years (making less of the interest savings matter)
- You're a consistent investor and will actually put the difference to work
- You want to maximize contributions to tax-advantaged accounts (401k, IRA) first
The Best of Both Worlds: The 30-Year with Extra Payments
A strategy many financial advisors recommend is taking the 30-year mortgage for its flexibility, but making extra principal payments regularly to pay it off faster and save on interest. Here's the impact of adding just $200–$500/month in extra principal to a 30-year mortgage:
| Extra Monthly Payment | Payoff Time | Interest Saved |
|---|---|---|
| $0 (standard) | 30 years | — |
| +$200/month | ~25 years | ~$80,000 |
| +$400/month | ~22 years | ~$130,000 |
| +$668/month (full 15yr diff) | ~15 years | ~$253,000 |
This approach gives you the lower required payment of a 30-year loan (protecting you if times get tough) while letting you pay it down as aggressively as you choose in good months. The key advantage over a true 15-year mortgage: you're never required to make the higher payment.
The Bottom Line
For most buyers who can genuinely afford the higher payment without stress, the 15-year mortgage is the financially superior choice — you'll save a substantial amount in interest and build wealth faster. But "can afford" means the payment is comfortable in your worst-case income scenario, not just your best-case scenario.
If the 15-year payment would be a stretch, the 30-year with aggressive voluntary extra payments gives you nearly the same benefits with far more flexibility.
Use our mortgage calculator to compare both scenarios with your actual numbers — plug in the same home price with each loan term to see exactly what the difference means for your monthly budget.