15-Year vs 30-Year Mortgage
It is the biggest either/or in home buying: spread the loan over 30 years and keep the payment low, or compress it into 15 years and pay the house off in half the time. The 15-year mortgage almost always carries a lower rate and costs dramatically less interest — but the payment is roughly 40–50% higher. This guide compares the two honestly, with one complete worked example, and shows the middle path many borrowers end up choosing.
Neither term is "better" in the abstract. The right answer depends on your cash flow, your other debts, and what you would realistically do with the money a cheaper payment leaves behind.
Why the 15-year costs so much less
Two separate effects stack in the 15-year loan's favor. First, lenders price it lower — a shorter loan is less risky for them, so the rate is commonly half a percentage point or more below the 30-year rate. Second, and far bigger, you are paying interest on the balance for half as many years. Interest is rent on money you still owe; owe it for 180 months instead of 360 and the rent bill collapses, even before the lower rate is counted.
The trade is monthly flexibility. The 15-year payment is a fixed obligation — in a bad month it is due in full, and the house is the collateral. The 30-year payment leaves a cushion you can invest, save, or simply survive on. Borrowers who choose the 30 earn less on paper only if that cushion actually gets invested; if it gets spent, the 15-year's forced discipline was the better financial product.
Worked example: a $350,000 loan at 6.5%
To keep the comparison clean, the example uses the same 6.5% rate for both terms — in the real market the 15-year rate would usually be lower, which would widen its advantage further. The loan is $350,000 (for example, a $437,500 home with 20% down, so no PMI in either case):
| Monthly payment — 30-year | $2,212.24 |
| Monthly payment — 15-year | $3,048.88 |
| Payment difference | $836.64 more per month |
| Total interest — 30-year | $446,405.71 |
| Total interest — 15-year | $198,797.64 |
| Interest saved by the 15-year term | $247,608.07 |
The numbers deserve a pause. The 30-year loan's interest — $446,405.71 — is more than the house loan itself. You borrow $350,000 and hand back nearly $796,406 over three decades. The 15-year loan returns $548,798 in total. The difference, about a quarter of a million dollars, is the true price of the lower monthly payment.
Equity builds faster too, for two reasons at once: the term is shorter, and a far larger share of each early payment is principal. On the 30-year loan, the first payment sends only $316.40 to principal; on the 15-year, $1,153.04. After seven years the 15-year borrower owes dramatically less — a real advantage if life makes you move sooner than planned.
The middle path: 30-year term, 15-year behavior
There is a well-known compromise: take the 30-year mortgage for its contractual safety, then voluntarily pay it as if it were a 15-year — adding the difference (here, about $837 a month) as extra principal. You capture most of the interest savings, and in a rough month you can fall back to the required payment without consequence. The savings are slightly smaller than the true 15-year because the rate is higher, but for many households the flexibility is worth more than the difference. Our guide to extra payments shows exactly how much a fixed monthly extra saves on a mortgage.
Two warnings attach to this strategy. It only works if the extra payments actually happen — set them up as an automatic transfer on payday, not a good intention. And confirm your servicer applies extras to principal, every time.
So which should you choose?
Choose the 15-year if your income is stable, you have an emergency fund, you carry no higher-rate debt, and the payment still leaves room to invest for retirement — capturing an employer match beats mortgage prepayment. Choose the 30-year if the 15-year payment would strain the budget, your income varies, or the difference would otherwise sit in a spending account rather than an investment. And whichever you pick, compare the "total interest" line before signing — it is the most honest single number in mortgage shopping.
Run your own comparison
Open the Mortgage Calculator and run your real price, down payment, and both terms through it — it includes taxes, insurance, and PMI, so the payment you compare is the one that will actually leave your account. Then test the middle path in the Loan Payoff Calculator by adding the payment difference as an extra monthly amount.
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Frequently asked questions
Why is the 15-year mortgage rate lower than the 30-year rate?
A shorter loan exposes the lender to less risk: the balance is repaid faster, and there are fewer years in which rates, home prices, or the borrower's circumstances can move against the lender. Less risk means a lower price, so 15-year rates typically sit about half a percentage point below 30-year rates.
How much more is a 15-year payment, really?
On the same loan amount and rate, about 38% more in our $350,000 example — $3,048.88 versus $2,212.24. Because the real-world 15-year rate is usually lower, the practical gap is often a bit smaller than a same-rate comparison suggests, but it remains a major monthly commitment.
Is paying a 30-year like a 15-year just as good?
Almost. You keep the right to fall back to the lower required payment, and you save most of the interest — but you pay the higher 30-year rate on the balance the whole time, so a true 15-year still wins on total cost. The strategy only works if the extra payments are automatic and actually happen.
Can I refinance from a 30-year into a 15-year later?
Yes, and many borrowers do once income rises. Weigh the closing costs against the remaining interest saved, and check how much of the 30-year term has already passed — refinancing late into a fresh 15-year can still save a great deal, but the math should be run, not assumed.
Should I choose the 15-year if it means investing less?
Usually not at the expense of an employer retirement match or basic liquidity. The reliable order is: emergency fund, employer match, high-interest debt, then mortgage acceleration. A house you cannot sell quickly is a poor substitute for cash in an emergency.