Choose the term by cash-flow tolerance
| Situation | What to do next |
|---|---|
| Stable surplus and long horizon | Compare the shorter term's interest savings with alternative uses of cash. |
| Variable income or thin reserves | Value the lower required payment and model optional prepayments separately. |
| Likely move or refinance | Compare cost and remaining balance through that expected month. |
Three differences that shape the answer
A shorter term usually raises the required payment and reduces scheduled interest.
The rate difference matters less than the payment difference when the budget is tight.
Compare both terms with the same loan amount, points and closing date.
Normalize both quotes
Request the same loan type, amount, down payment, lock period and point structure. A 15-year quote with points cannot be cleanly compared with a zero-point 30-year quote.
Compare the same loan amount and assumptions. The shorter term usually concentrates repayment into fewer months, so payment pressure can be materially higher even when its rate is lower.
Measure flexibility as well as interest
The required 30-year payment leaves more monthly room, but optional extra payments are not guaranteed. The 15-year loan creates forced faster amortization and less room during an income shock.
Place monthly payment, total scheduled interest and cash reserves side by side. Do not select the shorter term if the required payment leaves no room for maintenance, insurance changes or an income interruption.
Test the likely holding period
Compare principal, interest and remaining balance at the month you may sell or refinance. Lifetime interest is not the only useful horizon when few borrowers hold one mortgage for its full term.
Test a third path: a longer contractual term with voluntary principal payments. It can offer flexibility, but only if extra payments are applied to principal and the household can follow the plan consistently.
30-Year vs. 15-Year Mortgage: Payment and Interest comparison checklist
Which choice fits which situation
A shorter term usually raises the required payment and reduces scheduled interest.
Stable surplus and long horizon: Compare the shorter term's interest savings with alternative uses of cash.
Run both required payments with taxes, insurance and mortgage insurance included, then test whether the higher payment still works after an unexpected expense.
Primary sources
- CFPB: Buying a houseOfficial reference ↗
- CFPB: Mortgage resourcesOfficial reference ↗
Answers to check before you act
Is a 15-year mortgage always cheaper?
It generally schedules less interest for the same balance and rate assumptions, but its higher required payment can be a poor fit for a fragile budget.
Can I pay a 30-year mortgage like a 15-year loan?
Extra principal may accelerate payoff if the contract permits it, but voluntary payments do not create the same required schedule. Confirm how the servicer applies extra funds.