The short answer
A 15-year mortgage has a higher monthly payment but usually a lower rate, and costs far less interest overall. A 30-year mortgage keeps the payment lower and gives you more room in your budget. On a $300,000 loan the 15-year option costs about $595 more a month but saves roughly $234,000 in interest.
This is one of the few money decisions where the math is unambiguous and the right answer still depends on you. The 15-year loan wins on total cost every time. The 30-year loan wins on flexibility. The question is which one matters more for your life over the next decade — and there's a third option most comparisons skip.
On this page
The numbers side by side
15-year mortgages typically come with a lower rate than 30-year ones. In this example the 15-year rate is 0.75 percentage points lower — check current rates, but a gap of roughly half a point to a point is common.
| 30-year at 6.5% | 15-year at 5.75% | |
|---|---|---|
| Monthly payment | $1,896 | $2,491 |
| Total interest | $382,633 | $148,421 |
| Total repaid | $682,633 | $448,421 |
| Mortgage-free after | 30 years | 15 years |
The 15-year loan saves about $234,000 — not because of the lower rate alone, but because you're borrowing the money for half as long. In the early years of a 30-year mortgage, most of each payment is interest.
The third option: a 30-year loan you pay like a 15
Take the 30-year mortgage, then voluntarily pay more each month. Paying the 15-year amount ($2,491) on the 30-year loan above clears it in about 16 years, with around $187,000 of interest — not as cheap as the true 15-year loan (the rate is higher), but close.
The difference is that the extra payment is optional. Lose a job, have a baby or face a big repair, and you can drop back to the $1,896 minimum without asking anyone. That safety valve is worth a lot to some people and nothing to others.
Even a small extra amount helps. Adding $200 a month to the 30-year payment above pays it off about seven years early and saves roughly $103,000 in interest.
A 15-year mortgage makes sense if…
- The higher payment still fits comfortably, with savings left over every month.
- You already have a solid emergency fund and are saving for retirement.
- You want to be mortgage-free by a particular age — before retiring or before kids start university, for example.
- You know yourself: money left in your account tends to get spent rather than invested.
A 30-year mortgage makes sense if…
- The 15-year payment would stretch you, or leave nothing for emergencies.
- Your income is irregular — freelance, commission or seasonal.
- You'd invest the difference consistently. Over long periods, investments have often returned more than mortgage rates, though with risk.
- You have higher-interest debt to clear first — paying off a 22% credit card beats overpaying a 6.5% mortgage.
If you're not in the US
In the UK, Canada and Australia, the length of the mortgage (the term or amortization period) is separate from how long your rate is fixed — you might fix for two or five years on a 25-year term. The trade-off is the same, though: a shorter term means higher payments and much less interest. Use the mortgage calculator with your term in years.
Frequently asked questions
Is a 15-year mortgage worth it?
If the payment fits comfortably with savings left over, yes — you'll pay far less interest and own your home sooner. If it would stretch your budget, a 30-year loan with optional overpayments is safer.
Why are 15-year mortgage rates lower?
The lender's money is tied up for less time, so there's less risk from inflation and rate changes. Lenders pass part of that on as a lower rate.
How much more is a 15-year mortgage payment?
Often 25–35% more. On $300,000 at the rates above it's about $2,491 vs $1,896 a month.
Can I switch from a 30-year to a 15-year later?
You can refinance into a shorter term, though that has costs. Overpaying your existing mortgage gets much of the same benefit without refinancing.
OnlineToolPro Editorial Team
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The team behind OnlineToolPro. We write guides from building and testing these tools, and check platform rules against official documentation such as YouTube Help. When something changes, we update the article and its date.