Key takeaways
- A longer term spreads the same principal over more payments, so each payment is smaller, but you pay interest on the balance for more months.
- On a $30,000 loan at 7%, stretching from 36 to 84 months cuts the payment by $474 but more than doubles the interest, from $3,347 to $8,034.
- Longer loans usually carry higher rates too, which makes the gap even bigger.
- Choose the shortest term whose payment fits comfortably in your budget, not the lowest payment a lender will offer.
When you shop for a loan, the monthly payment gets all the attention. But the term, meaning how many months you take to repay, quietly decides how much the loan costs in total. A longer term lowers the payment and raises the price.
Why longer terms cost more
Each month, interest is charged on your remaining balance. A longer term means smaller principal payments, so the balance falls more slowly and there’s more balance left to charge interest on, for more months.
Auto loan example: same rate, different terms
Here’s a $30,000 loan at 7% APR over five common auto-loan terms:
| Term | Monthly payment | Total interest | Total paid |
|---|---|---|---|
| 36 months | $926.31 | $3,347 | $33,347 |
| 48 months | $718.39 | $4,483 | $34,483 |
| 60 months | $594.04 | $5,642 | $35,642 |
| 72 months | $511.47 | $6,826 | $36,826 |
| 84 months | $452.78 | $8,034 | $38,034 |
Notice the diminishing return on the payment. Going from 36 to 48 months lowers the payment by $208. Going from 72 to 84 months lowers it by only $59, but still adds $1,208 of interest.
More realistic: longer terms, higher rates
Lenders usually charge more for longer loans. Here’s the same $30,000 with illustrative rates that rise with the term:
| Term | Rate | Monthly payment | Total interest |
|---|---|---|---|
| 36 months | 6.5% | $919.47 | $3,101 |
| 48 months | 6.75% | $714.91 | $4,316 |
| 60 months | 7% | $594.04 | $5,642 |
| 72 months | 7.75% | $522.34 | $7,609 |
| 84 months | 8.5% | $475.09 | $9,908 |
Now the 84-month loan costs $9,908 in interest, about 3.2 times the 36-month loan, for a payment that’s $444 a month lower.
The hidden risk with long car loans: negative equity
Cars lose value quickly, often fastest in the first few years. With a long term, your balance falls slowly. On the 84-month loan above, you’d still owe $19,275 after three years, compared with $13,268 on the 60-month loan.
If the car is worth less than you owe, you have negative equity. That’s a problem if the car is totaled (insurance pays its value, not your balance, unless you have gap coverage) or if you want to trade it in. Rolling negative equity into your next loan starts that loan underwater too.
Mortgage example: 15 vs. 30 years
The same trade-off applies to mortgages, at a much larger scale. On a $360,000 loan, with illustrative rates of 5.75% for 15 years and 6.5% for 30 years:
| 15-year at 5.75% | 30-year at 6.5% | |
|---|---|---|
| Monthly principal & interest | $2,989.48 | $2,275.44 |
| Total interest | $178,106 | $459,160 |
The 15-year loan costs $714 more a month but saves $281,054 in interest. Some borrowers choose the 30-year for its lower required payment and prepay it like a 15-year when they can. See how extra mortgage payments save money.
How to choose a term
- Start from your budget, not the lender’s offer. Decide the payment you can comfortably afford alongside savings and other goals.
- Pick the shortest term that fits that payment. If the only way a loan fits is a very long term, the loan may be too big.
- Compare total cost, not just APR. Two loans with the same APR but different terms can differ in total interest by thousands of dollars.
- Check for prepayment penalties. If there are none, a slightly longer term you pay down faster keeps flexibility for a tight month.
The loan calculator and auto loan calculator show the payment, total interest, and full amortization schedule for any term. The amortization calculator shows how the balance falls month by month.