15-Year vs 30-Year Mortgage: Which Saves You More?
A 15-year mortgage requires a higher monthly payment but slashes total interest paid by roughly $200,000 on a $400,000 loan. The 30-year mortgage offers lower required payments and more flexibility. The right choice depends on your income stability, cash flow needs, and how quickly you want to own your home outright.
The Core Tradeoff
Both loan terms let you borrow the same amount. The 30-year mortgage spreads that borrowing over twice as many payments, lowering the required monthly amount. The 15-year concentrates payback into half the time — which means higher payments but dramatically less interest paid to the bank.
Side-by-Side: $400,000 at Current Market Rates
The example below uses rates representative of the spread between 15- and 30-year products (30-year at 7.0%, 15-year at 6.375%, a ~0.625% differential):
| 30-Year at 7.0% | 15-Year at 6.375% | |
|---|---|---|
| Monthly P&I | $2,661 | $3,456 |
| Monthly difference | — | +$795 |
| Total paid over life | $957,960 | $622,080 |
| Total interest paid | $557,960 | $222,080 |
| Interest saved | — | $335,880 |
The 15-year mortgage costs $795 more per month but saves over $335,000 in interest.
Compare 15-Year vs 30-Year Payments on Your Loan
Enter your loan amount and see the monthly payment and total cost for both terms
When the 30-Year Makes More Sense
Cash flow flexibility is a priority. If your income varies — you're self-employed, commission-based, or in an industry with cyclical layoffs — the lower required payment of a 30-year mortgage provides a cushion. You can always pay more, but you can't pay less than the minimum.
You have high-rate debt. If you're carrying credit card balances at 18%–24% APR or other high-rate debt, the $795/month difference is likely better deployed paying those off first.
You're early in your career. A 30-year mortgage on your first home, followed by refinancing or accelerated payments as your income grows, can be a sound strategy.
When the 15-Year Makes More Sense
Income is stable and high. The higher payment requires confidence in your monthly cash flow. If $795 extra per month does not materially strain your budget, the interest savings are compelling.
You want to retire mortgage-free sooner. A 30-year mortgage started at age 40 extends to 70. A 15-year term reaches payoff at 55, freeing up the housing payment during peak retirement savings years.
You value forced savings. Building equity aggressively through the 15-year structure is a form of forced savings that many people find easier to maintain than discretionary investing.
The Middle Path: 30-Year Loan, 15-Year Payments
You can take a 30-year mortgage and simply pay the 15-year payment amount each month. This gives you the payoff timeline of a 15-year loan while retaining the option to pay only the lower required amount if your circumstances change. You lose the slightly lower rate, but you gain maximum financial flexibility.
Key Takeaways
- On a $400,000 loan, a 15-year term saves roughly $335,000 in interest versus a 30-year term.
- The 15-year payment is $795/month higher in this example — a meaningful cash flow commitment.
- 15-year rates are typically 0.5%–0.75% lower than 30-year rates, compounding the savings.
- A 30-year loan with voluntary 15-year-level payments offers a hybrid approach with extra flexibility.
Is the interest rate lower on a 15-year mortgage?▾
Yes, typically by 0.5%–0.75%. Lenders offer lower rates on shorter terms because they recover their money faster and face less long-run default risk. On a $400,000 loan, a 0.625% rate differential translates to an additional $90–$100/month in savings on top of the principal interest-math advantage of the shorter term.
Can I get the benefits of a 15-year mortgage while keeping the 30-year payment flexibility?▾
Yes. You can take a 30-year mortgage and voluntarily pay the 15-year payment amount each month. If your finances are disrupted — job loss, medical expenses — you can drop back to the required 30-year payment. This strategy provides the interest savings of aggressive paydown with the safety net of a lower required payment. The only thing you give up is the slightly lower rate that a formal 15-year mortgage would carry.