The 30-year vs 15-year mortgage decision is one of the most important choices a homebuyer makes. A 15-year mortgage saves over $330,000 in interest on a $400,000 loan compared to a 30-year term – but comes with significantly higher monthly payments. This guide gives you real numbers to make the right call for your budget.
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The 30-year vs. 15-year mortgage debate is one of the most consequential financial decisions homebuyers face – and the right answer isn’t the same for everyone. The 15-year mortgage saves an enormous amount of interest and builds equity twice as fast. The 30-year mortgage offers a much lower monthly payment and greater financial flexibility. Both are correct choices depending on your situation.
Here’s a complete, numbers-first breakdown to help you decide.
Monthly Payment Comparison
The most immediate difference between a 15-year and 30-year mortgage is the monthly payment. On a $400,000 loan in mid-2026:
| Loan Amount | 15-Year @ 6.5% | 30-Year @ 7.0% | Monthly Difference |
|---|---|---|---|
| $200,000 | $1,742/mo | $1,331/mo | +$411 for 15-yr |
| $300,000 | $2,613/mo | $1,996/mo | +$617 for 15-yr |
| $400,000 | $3,485/mo | $2,661/mo | +$824 for 15-yr |
| $500,000 | $4,356/mo | $3,327/mo | +$1,029 for 15-yr |
| $600,000 | $5,227/mo | $3,992/mo | +$1,235 for 15-yr |
The 15-year payment is roughly 30–35% higher each month. On a $400,000 loan that’s an extra $824/month. That’s a real budget impact – and it’s why most buyers choose the 30-year mortgage even when the 15-year would save them more.
Total Interest: The Real Savings
The higher monthly payment of the 15-year mortgage buys you something remarkable: a dramatically lower total cost. Here’s where the numbers become eye-opening.
On a $400,000 mortgage:
15-year at 6.5%: $3,485/month · Total paid: $627,300 · Total interest: $227,300
Interest saved with 15-year: $330,660 – that’s more than 80% of the original loan amount.
The lower rate on a 15-year mortgage (typically 0.5–0.75% below 30-year rates) compounds the savings further. You’re not just paying for 15 fewer years – you’re also paying a lower rate on every dollar for those 15 years.
Side-by-Side for Every Loan Amount
| Loan Amount | 15-yr Total Interest | 30-yr Total Interest | You Save with 15-yr | Equity at Year 5 |
|---|---|---|---|---|
| $200,000 | $113,700 | $279,000 | $165,300 | $76K (15-yr) vs $17K (30-yr) |
| $300,000 | $170,500 | $418,500 | $248,000 | $114K vs $26K |
| $400,000 | $227,300 | $558,000 | $330,700 | $152K vs $34K |
| $500,000 | $284,200 | $697,200 | $413,000 | $190K vs $43K |
The equity difference at Year 5 is equally striking. A 15-year mortgage borrower has paid down nearly 4× more principal in the same time frame – which matters enormously if you need to sell, refinance, or tap home equity.
Use our mortgage calculator to run these numbers for your exact loan amount and current rates.
Who Should Choose the 30-Year Mortgage
30-Year Makes Sense When…
- The higher 15-year payment would stretch your budget uncomfortably
- You have high-interest debt (credit cards, personal loans) to eliminate first
- You’re early in your career with income expected to grow significantly
- You have an emergency fund below 3–6 months of expenses
- Your employer offers strong 401(k) matching you haven’t maxed
- You’re buying in a high-cost market where the 15-year payment is simply unaffordable
- You value cash flow flexibility for investment opportunities
- You plan to move or sell within 7–10 years (total interest matters less)
15-Year Makes Sense When…
- The higher monthly payment fits your budget without stress
- You’re in your 40s or 50s and want to be mortgage-free before retirement
- You’ve already maxed retirement accounts and have emergency savings
- You want the guaranteed “return” of eliminating mortgage interest
- Your income is stable and unlikely to drop unexpectedly
- You value the psychological security of owning your home outright
- You’re buying a modest home where the payment difference is manageable
- You follow the Dave Ramsey approach (see our payoff calculator)
The Retirement Argument for the 15-Year
One of the strongest arguments for the 15-year mortgage is retirement timing. If you’re 40 years old when you buy a home, a 30-year mortgage means you’re still making mortgage payments at age 70. A 15-year mortgage has you mortgage-free at 55 – with 10–15 years to redirect that monthly payment into retirement savings at the highest-earning years of your career.
The math on this is compelling: if a 45-year-old redirects $824/month (the 15-yr vs.
30-yr payment difference on a $400K loan) into a retirement account at 7% returns starting when the 15-year mortgage is paid off at age 60, they accumulate roughly $170,000 in additional retirement assets over 5 years before traditional retirement age – on top of the $330,000 in interest they didn’t pay.
The “Invest the Difference” Strategy
The most common counterargument to the 15-year mortgage goes like this: take a 30-year mortgage, invest the monthly payment difference ($824/month in our $400K example) in the stock market, and earn more in returns than you would have saved in mortgage interest.
This math can work – especially when mortgage rates are low. At a 7% mortgage rate vs. a historical 10% stock market return, the spread is only 3 percentage points. But several factors complicate this:
Most people don’t actually invest the difference. In theory, the extra cash flow from a 30-year payment goes to investing. In practice, lifestyle inflation absorbs it. The 15-year mortgage is a forced savings mechanism – you can’t spend the equity you’re building.
Investment returns aren’t guaranteed; mortgage savings are. Paying down a 7% mortgage delivers a guaranteed 7% return. Stock returns average around 10% historically but with significant volatility – including years of negative returns right when you might need the money.
At current rates (6.5–7%+), the math tilts toward the 15-year. The lower the mortgage rate, the stronger the case for investing. The higher the rate, the more compelling the guaranteed savings of the 15-year become. At 7%, most financial advisors consider it a wash at best.
The Verdict: Which One Saves More?
The 15-year mortgage unambiguously saves more money.
On a $400,000 loan at current rates, you’ll save over $330,000 in interest with a 15-year mortgage versus a 30-year.
That interest savingsD you’ll own the home outright in half the time. The question isn’t which one saves more. The question is whether the higher monthly payment fits your budget and life stage. If it does, the 15-year mortgage is almost always the better financial choice at today’s rates.
Our recommendation: Use our mortgage calculator to compare both options at your exact loan amount. Then run the 15-year payment against the 28/36 rule to see if it fits your income. If the 15-year passes the 28% test comfortably, it’s worth the higher payment. If it pushes you over 25% of take-home pay, the 30-year gives you breathing room you may genuinely need.
And if you choose a 30-year mortgage, use our mortgage payoff calculator to see how making one extra payment per year or rounding up your payment closes the gap – giving you many of the benefits of a 15-year without the locked-in higher payment.
Run the Numbers for Your Loan
Compare 15-year vs. 30-year payments, total interest, and payoff scenarios.
🏠 Mortgage Calculator
💳 Payoff Calculator
📐 28/36 Rule Guide
When weighing a 30-year vs 15-year mortgage, most borrowers focus only on the monthly payment difference – but the total interest gap is where the real decision lies. A 30-year vs 15-year mortgage comparison on a $400,000 loan at current rates shows the 15-year saves over $160,000 in interest over the life of the loan.
30-Year vs 15-Year Mortgage: Frequently Asked Questions
Is a 30-year vs 15-year mortgage decision permanent? No – you can refinance a 30-year mortgage into a 15-year at any point if your income grows. Many borrowers start with a 30-year for flexibility, then refinance.
Which is better for first-time buyers: a 30-year vs 15-year mortgage? Most first-time buyers choose a 30-year mortgage for its lower required payment, then make extra principal payments when possible to shorten their payoff timeline.
How much can I save with a 15-year vs 30-year mortgage? On a $400,000 loan at 6.5%, a 15-year mortgage saves approximately $163,000 in total interest compared to a 30-year. Use our 30-year vs 15-year mortgage calculator for your exact numbers.
Sources & Further Reading
Mortgage rate data in this guide is sourced from the Freddie Mac Primary Mortgage Market Survey (updated weekly) and the CFPB mortgage loan options guide. Use our free 30-year vs 15-year mortgage calculator to compare payments on your specific loan amount.