One saves you two hundred thousand dollars. The other keeps eight hundred a month in your pocket. Here is how to decide which matters more in your situation.
The trade-off in one paragraph
A 15-year mortgage costs substantially more each month but dramatically less overall, because you're borrowing for half as long and usually at a lower rate. A 30-year mortgage costs less monthly and far more in total, but leaves room in your budget for everything else. Neither is universally right.
What the numbers look like
A $320,000 mortgage, with the 15-year priced roughly 0.6 points below the 30-year:
The 15-year costs about $660 more a month and saves roughly $245,000 in interest. Those are both big numbers, which is exactly why the decision is hard.
The case for 30 years
Flexibility is worth something
The lower required payment is a floor, not a ceiling. You can take a 30-year mortgage and voluntarily overpay it like a 15-year — but in a bad month you're allowed to stop. With a 15-year loan, the higher payment is contractual.
It frees money for other goals
That $660 difference could go to retirement contributions, an emergency fund, or childcare. Money locked in home equity is genuinely locked — getting it back means selling or borrowing against it.
You may qualify for more house
Because lenders assess affordability on the monthly payment, a 30-year term stretches your approval further. Whether that's a benefit or a temptation depends on you.
The case for 15 years
The interest saving is enormous
Nearly a quarter of a million dollars in the example above. That's not an abstract figure — it's a real amount of money that stays with you rather than going to a bank.
Lower rates
15-year mortgages consistently price below 30-year ones, because the lender's risk window is shorter. The gap varies but is typically half a point or more.
You build equity far faster
On a 30-year loan, the early years are overwhelmingly interest. A 15-year loan reaches meaningful equity years sooner, which matters if you might move or need to borrow against the house.
It ends
Being mortgage-free at 50 rather than 65 changes what the rest of your working life looks like. That's hard to price and easy to undervalue at 30.
The honest test: could you comfortably afford the 15-year payment and still fund your retirement, emergency fund, and normal life? If yes, it's usually the better deal. If it would mean skipping retirement contributions, take the 30-year — the employer match and tax advantages of retirement accounts usually beat the mortgage interest saving.
The middle path most people miss
Take the 30-year mortgage and pay it like a 20- or 25-year one. You capture most of the interest saving while keeping the lower payment as a safety valve.
Two conditions: confirm your servicer applies extra payments to principal rather than treating them as prepaying your next bill, and actually make the overpayments — the plan only works if you follow it.
What about investing the difference?
The standard argument says take the 30-year and invest the $660 monthly difference, since long-run market returns have historically exceeded mortgage rates. The maths often supports this.
Two honest caveats. First, it only works if you genuinely invest the difference every month rather than spending it — and many people don't. Second, paying down a mortgage is a guaranteed return at your interest rate, while market returns are not guaranteed at all. A guaranteed 6.5% is worth more than most people credit.
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