15 vs 30 Year Mortgage: Payments, Interest and Remaining Debt
Examples reviewed 15 September 2026. Calculated from the same engines used by the linked tools.
A shorter term repays principal faster and raises the required monthly payment. A longer term reduces that commitment but leaves more debt outstanding. Compare both the monthly budget and the cost over the period you expect to keep the loan.
Same-rate worked example
Both loans borrow USD300,000 at an illustrative fixed 6% nominal annual rate with monthly payments and no upfront costs. These are assumptions, not available mortgage offers.
| Measure | 15 years | 30 years |
|---|---|---|
| Monthly principal and interest | US$2,531.57 | US$1,798.65 |
| Lifetime interest | US$155,682.69 | US$347,514.57 |
| Debt remaining after five years | US$228,027.30 | US$279,163.07 |
| Five-year interest and fees | US$79,921.52 | US$87,082.16 |
What changes the decision?
Actual rates and fees can differ between terms. If you sell or refinance early, compare interest and fees through that date alongside the remaining balance. Lower cash payments alone do not establish lower borrowing cost because principal repayment builds equity.
This example excludes property taxes, insurance, maintenance, prepayments and the investment return on spare cash. It does not assess affordability or approval.
Who the 15-year loan suits, and when the 30-year wins
The 15-year mortgage suits a household whose income comfortably covers the higher payment and who would not otherwise invest the difference: it forces the saving and roughly halves the lifetime interest. The 30-year loan wins when the payment gap would strain the budget, when the money would go to higher-return uses such as paying off card debt or an employer-matched pension, or when the buyer expects to move within a few years, since the remaining balance after five years differs less than the lifetime figures suggest. A common middle path is the 30-year loan paid as if it were a 15-year one: the same payoff when times are good, and the lower required payment when they are not, at the cost of a slightly higher rate. Run a 15 vs 30 year mortgage calculator on your own rate quotes before deciding, because lenders usually price the two terms differently and that gap changes the answer.
Compare your own mortgage offers using separate rates, fees and a holding period.