15- vs. 30-Year Mortgage: Which Should You Choose?
A 15-year mortgage saves a fortune in interest; a 30-year keeps your payment low and flexible. A side-by-side example on a $400,000 loan, and how to decide.
The short version
- 15-year loans carry a lower rate and cut total interest dramatically — but the monthly payment is much higher.
- 30-year loans have a lower, more flexible payment, at the cost of far more interest over time.
- On a $400,000 loan, the 30-year can cost over $300,000 more in interest than the 15-year.
- A middle path: take the 30-year for flexibility and pay extra when you can.
Choosing between a 15- and a 30-year mortgage is really a choice between two goals: paying the least interest, or keeping the most cash free each month. Both are valid — they just serve different situations. Here’s the trade-off in real numbers, and how to decide.
The core trade-off
A 15-year loan pays off in half the time, and lenders reward that shorter risk with a lower interest rate — recently about 0.6–0.7 percentage points below the 30-year. You pay far less interest and build equity fast. The catch: the monthly payment is much higher, because you’re compressing the same balance into half as many payments.
A 30-year spreads the loan out, so the payment is lower and easier to carry — leaving room for investing, saving, or simply breathing. The cost is that you pay interest for twice as long, and it adds up to a lot.
A $400,000 loan, side by side
| 30-year (6.7%) | 15-year (6.0%) | |
|---|---|---|
| Monthly payment (P&I) | $2,581 | $3,375 |
| Total interest | $529,200 | $207,577 |
| Interest saved with 15-year | — | ~$321,600 |
The 15-year costs about $794 more a month — but saves more than $321,000 in interest over the life of the loan. That’s the whole decision in one table: a higher payment now versus a fortune in interest later.
Who each one suits
- Choose the 15-year if the higher payment fits comfortably within your budget and your top priority is owning the home outright sooner with minimal interest.
- Choose the 30-year if you want a lower, safer payment, value the flexibility, or would rather invest the difference — potentially earning more than the mortgage rate.
The middle path: 30-year, paid like a 15
You can take the 30-year for its low required payment, then add extra principal whenever you can. You keep the flexibility to drop back to the smaller payment in a tight month, while still cutting years and interest off the loan. It’s the best of both for many buyers.
Compare your own loan
Run your loan amount at both terms and rates to see the payment and total interest side by side.
Try the calculator
Mortgage CalculatorFree mortgage calculator. Estimate your monthly payment with principal, interest, taxes, insurance, and PMI, plus a full amortization schedule.Leaning toward the 30-year but want to pay it down faster? See how much time and interest an extra monthly payment saves.
Sources
This article is for general education and is not financial, tax, or legal advice. Figures reflect published 2026 IRS and SSA amounts as of the date above; verify current limits with the linked sources or a qualified professional before acting.
About the author
David Miles is the founder of FigureMoney and builds independent, source-backed personal-finance tools across the Modern Site Builders network. Every calculator and guide cites the IRS, SSA, or primary research behind its numbers.
Calculators in this guide
Mortgage Calculator
Free mortgage calculator. Estimate your monthly payment with principal, interest, taxes, insurance, and PMI, plus a full amortization schedule.
Mortgage Payoff Calculator
See how extra monthly payments shorten your mortgage and cut total interest. Enter your loan and an extra amount to find your new payoff date and interest saved.
Home Affordability Calculator
Find out how much house you can afford. Enter your income, debts, and down payment to see your target home price and monthly payment, using the 28/36 rule.
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