15-Year vs 30-Year Mortgage: Payment vs Total Interest
A **15-year** loan pays off faster with less total interest but a **higher monthly payment**. A **30-year** loan maximizes payment flexibility and often qualifies for larger loans, but you pay more interest if you keep it full term.
Step by step
1. Compare P&I at the same loan amount
Hold price and down payment constant; only change term and rate (15-year rates are usually lower).
2. Sum total interest
Multiply monthly savings of 30-year by months held—but add interest delta if you invest the payment difference instead.
3. Consider prepayment option
30-year with extra principal can mimic 15-year flexibility while preserving lower required payment in bad months.
15-year vs 30-year
15-year is a forced savings plan; 30-year plus voluntary prepay adds flexibility.
- 15-year: Higher payment; less interest; faster equity.
- 30-year: Lower required payment; more interest if no prepay.
- Rate spread: 15-year APR often 0.25–0.75% lower than 30-year—run both quotes.
- Investing difference: If invested payment gap beats after-tax mortgage rate, 30-year can win on paper.
Use our calculators
Common mistakes
- Choosing 15-year without emergency fund
- Ignoring opportunity cost of payment difference
FAQ
Can I pay a 30-year like a 15-year?
Yes—extra principal payments accelerate payoff without locking the higher required payment.
Which builds equity faster?
15-year amortizes principal faster by schedule; extra payments on 30-year close the gap.