Finance category
Mortgage, loan, investing, tax, and money calculators.
15-Year vs 30-Year Mortgage Calculator
Compare a 15-year mortgage to a 30-year mortgage at the rates you've been quoted. See the monthly payment difference, total interest savings, and the cash-flow trade-off.
30-year payment
$2,661
Total: $958,036
Interest: $558,036
15-year payment
$3,430
Total: $617,344
Interest: $217,344
Monthly payment difference
+$768
extra cash needed each month
Interest saved on 15
$340,691
over the life of the loan
How to think about it
The 15-year saves enormous interest but requires roughly 29% more cash flow each month. That extra commitment can crowd out retirement contributions, emergency reserves, or down payment savings for the next move.
Many borrowers split the difference: take a 30-year loan and add the difference as principal payment when they can. That keeps the floor flexible if income drops while still attacking principal aggressively.
How to Use
- Enter the same loan amount you'd borrow on either term.
- Enter the rate you've been quoted on the 30-year.
- Enter the rate you've been quoted on the 15-year (typically 0.5–0.75% lower).
- Compare monthly payment, total cost, and interest saved on the 15-year.
- Decide whether the cash-flow flexibility of the 30 outweighs the lifetime interest savings of the 15.
Frequently Asked Questions
Is a 15-year always better mathematically?
Yes for total interest cost — the lower rate plus shorter term usually saves a third or more of the lifetime interest. The trade-off is cash-flow flexibility: the 15-year payment is materially higher and locked in.
Why does a 15-year usually have a lower rate?
Lenders price 15-year loans lower because they take on less duration risk. The shorter average life makes them easier to hedge and securitize at a tighter spread.
What if I want the 15-year savings without the obligation?
Take the 30-year and add the payment difference as extra principal each month. You'll save most of the interest while keeping the floor low if income drops or unexpected expenses hit.
Does the 15-year build equity faster?
Much faster. By year 5 a 15-year loan is roughly 30% paid down vs about 10% on a 30-year. That equity is real money if you sell, refinance, or borrow against it.
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