15-Year vs 30-Year Mortgage: Which Saves You More?
By Arshi Khan, Founder of Just4Marketing · October 26, 2026 · 6 min read
Payments, total interest and equity for a 15-year and a 30-year mortgage side by side, what paying a 30-year loan like a 15 costs, and how to choose.
The two most common mortgage terms trade the same thing in opposite directions. A 30-year loan gives you a lower monthly payment; a 15-year loan gives you a much lower total cost. Which one is right depends less on the math — which clearly favours the 15-year — and more on how much room your budget needs.
The numbers side by side
Take a $300,000 loan. Fifteen-year mortgages usually come with a lower rate than 30-year ones, so this example uses 5.75% for 15 years and 6.5% for 30 years. Your lender's actual rates will differ.
| 15-year at 5.75% | 30-year at 6.5% | |
|---|---|---|
| Monthly payment (P&I) | $2,491.23 | $1,896.20 |
| Total interest | About $148,400 | About $382,600 |
| Balance after 10 years | About $129,600 | About $254,300 |
| Debt-free in | 15 years | 30 years |
The 15-year loan costs $595 more a month but saves about $234,000 in interest — more than the loan's value in some areas. It also builds equity far faster: after ten years you'd owe roughly half as much.
Why the gap is so large
Two things work together. First, the 15-year loan has a lower rate. Second, and more importantly, the balance falls twice as fast, so interest is charged on a smaller amount every month. On the 30-year loan, the first year's payments are about 85% interest and only 14% of the very first payment reduces the balance. On the 15-year loan, about 42% of the first payment goes to principal, and the share passes half within three years.
The middle path: a 30-year loan paid like a 15
Some buyers take the 30-year loan for its lower required payment, then pay extra whenever they can. If you paid the 15-year amount ($2,491.23) on the 30-year loan every month, you'd be debt-free in about 16 years and 4 months and pay about $187,200 in interest.
That's about $38,700 more than the true 15-year loan, because of the higher rate — the price of keeping the option to drop back to $1,896 in a tight month. Whether that flexibility is worth it is a personal call.
Choose the 15-year if…
- the higher payment still keeps your housing costs comfortably within your budget,
- you already have an emergency fund and are saving for retirement,
- you want to be mortgage-free by a certain age, or
- you know you won't reliably make extra payments on your own.
Choose the 30-year if…
- the 15-year payment would stretch you, or would limit you to a smaller home than you need,
- your income varies and you want a lower required payment,
- you'd rather invest the difference or still need to build savings, or
- you plan to pay extra when you can and value the flexibility.
A 20-year loan is a useful compromise too: its payment sits between the two, and it still saves a large share of the interest.