30-Year vs 15-Year Mortgage
Data as of Oct 22 2026
A 15-year mortgage costs more every month and far less in total. On a $350,000 loan at today's rates the monthly difference is $679, and the lifetime interest difference is $310,482. Which is right depends less on that arithmetic — it is not in dispute — than on whether the higher payment is genuinely sustainable for the next fifteen years.
The rate gap is real, and it is not small
Freddie Mac's weekly survey currently puts a 30-year fixed at 7.32% and a 15-year fixed at 6.68% — a spread of 0.64 percentage points. Shortening the term is paid for twice: a bigger monthly payment and a shorter period to make it in.
Payment and total interest, side by side
| Term | Rate | Monthly P&I | Total interest |
|---|---|---|---|
| 30-yr fixed | 7.32% | $2,404 | $515,533 |
| 20-yr fixed | 7.20% | $2,756 | $311,373 |
| 15-yr fixed | 6.68% | $3,084 | $205,051 |
Monthly principal and interest on a $350,000 loan; total interest is over the full term. Rates are Freddie Mac PMMS Oct 22 2026. The 20-year figure is derived — PMMS publishes no 20-year series (see lib/site.js for the derivation).
The 20-year term in the middle
PMMS publishes no 20-year series, so this site derives one as the 30-year rate minus 0.18 times the 30/15 spread — currently 7.20%. It sits between the other two on both payment and total interest, and it is a genuinely useful compromise that many borrowers are never quoted. Treat the derived figure as an estimate and confirm the real rate with a lender.
When the 15-year is the wrong choice
- When the higher payment leaves no cash reserve. The two worst outcomes in a mortgage are default and an emergency funded at credit-card rates.
- When you may move within a few years. The 15-year's advantage is back-loaded, so a short hold reduces it toward the rate difference alone — which is smaller than the interest saving.
- When the payment is affordable only because you would stop contributing to a retirement account. Repaying a 7.32% mortgage is a strong guaranteed return, but not at the cost of an employer match.
- When it forces a smaller or worse-located house than you need, and you would end up moving or refinancing anyway.
Getting most of the benefit while keeping the 30-year
Extra principal payments on a 30-year loan behave much like a 15-year without the contractual obligation. Paying an extra $679 a month on the 30-year loan in the table pays it off in about 16.2 years and saves $267,792 of interest — not quite the 15-year outcome, because the rate is higher, but close. The difference is that in a bad month you can stop, which is precisely what a 15-year contract does not let you do.
The calculator's extra-payment field runs exactly this scenario and reports the payoff month and the interest saved.
Frequently asked questions
How much more is a 15-year mortgage each month?
$679 more on a $350,000 loan at today's rates — $3,084 against $2,404 of principal and interest.
How much does a 15-year mortgage save in interest?
On a $350,000 loan at today's rates, $205,051 of total interest against $515,533 for the 30-year — a saving of $310,482, the largest single lever available to a borrower who can sustain the payment.
Should I choose a 15-year mortgage?
If the payment is comfortable, your income is stable, and you keep three to six months of expenses in reserve, the interest saving is compelling. If any of those is not true, take the 30-year and prepay — you keep the option to stop.
What about a 20-year mortgage?
It is the middle option and often the best compromise. It carries a rate below the 30-year, a payment well below the 15-year, and it clears the loan five to ten years earlier. Note that PMMS has no 20-year series, so the rate this site shows for it is derived from the 30/15 spread.
Is the 15-year rate always lower than the 30-year?
Historically yes, because the lender takes less duration risk. The spread widens and narrows with the market and can compress sharply when the yield curve is flat, but the 15-year is normally below the 30-year.
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FHA and conventional mortgages compared on down payment, credit score and mortgage insurance — including when the insurance stops, which is what decides it.
Property tax rates for all 50 states and DC ranked by effective rate, with the median annual bill and how the tax is actually calculated.
Freddie MacU.S. Census BureauFannie MaeU.S. Department of Housing and Urban Development (HUD)U.S. Department of Veterans AffairsPrivate mortgage insurersNAICState statutes and departments of revenue