If people put everything from groceries to gas on credit cards to earn rewards, why not college tuition?

Many colleges and universities let you pay with plastic, and some people do. But it can be a very poor financial decision, and it may cost you more in the long run.

Sallie Mae’s report “How America Pays for College 2016” found that about 2 percent of families with students used credit cards to pay for college costs, putting an average of $4,443 on the cards for tuition and other expenses to attend school. About 5 percent of students used credit cards, charging about $1,615. But here are some things to think about before you put down the plastic:

CONVENIENCE FEES: Students and families who pay tuition bills with a credit card incur, on average, a “convenience fee” of 2.62 percent, according to a recent Creditcard.com survey of 300 of the largest U.S. public, private and community colleges. That means if you are paying $10,000 in tuition, you are also facing $262 in fees.

The fees help school cover the cost of processing the cards and vary greatly by location and type of school.

Creditcards.com found that community colleges are the most fee-friendly — only 8 percent of those that accept cards charge convenience fees. By contrast, 93 percent of public universities and 77 percent of private institutions that accept credit cards charge convenience fees.

“College is expensive enough without having to pay an additional 2 to 3 percent to pay with plastic,” said Matt Schulz, CreditCards.com’s senior industry analyst.

The fees are not always immediately evident and might not be made clear until you are into the payment processing system, so it may be worth a call to your school to find out if they charge them.

INTEREST: If you are not able to pay off the balance on your credit card, then definitely do not use it.

The interest you pay would greatly outweigh any benefits you’d receive as a cardholder. And it would dwarf any convenience fee you would pay, Schulz said.

Consider lower-interest means of borrowing to pay for school, such as student loans.

REWARDS: The College Board says that yearly fees and tuition run, on average, from $3,440 for a local student at a public two-year college to $32,410 for a private four-year college. That’s a lot of potential miles, reward points or cash back.

But it only makes sense to charge your tuition if all these criteria apply: your card issuer offers rewards but doesn’t charge a convenience fee, and you’re able to pay off the balance within the billing cycle to avoid interest.

“If you can do all of those things, it makes sense to charge your tuition, but beyond that, the math just doesn’t work in your favor,” Schulz said.