There is the cost of college, and then there is the cost of going to college — everything from the extra-long twin bed sheets you’ll need for your dorm room to textbooks for class.

The expenses can add up fast.

During the 2014-15 school year, the average full-time undergraduate student at a four-year public university spent $1,225 on books and supplies. At four-year private colleges, the average student shelled out $1,244.

As for back-to-school shopping, an annual survey by the National Retail Federation found that, on average, college students and their families will spend just under $900 this year on dorm items, clothes and electronics, among other things.

If you’re heading to college this fall, consider the following tips for how to save.

Cut textbook expenses. The days of buying all of your textbooks from the campus bookstore are over. Today, you have multiple ways to get course materials, including renting books, downloading digital versions or buying used books online.

To get started, use a search engine that compares the cost of buying or renting a specific textbook across multiple websites.

Bigwords.com, for example, aggregates prices for used and new books, as well as rentals and e-books. In addition to taking into account shipping costs, Bigwords will also scour for coupons and promotions.

Shopping around can pay off. A new copy of the sixth edition of “Macroeconomics: Principles and Applications,” by Robert E. Hall and Marc Lieberman, goes for $286 at one college bookstore. A search through Bigwords, however, found a rental option for as little as $27 for the semester, and a used copy starting at $70.

Check coupon sites. Just as with any purchase you make online, it’s a good idea to check for coupon codes or promotions while shopping the Web for school supplies. Retailers are running plenty of back-to-school specials right now.

Coupons.com, for example, recently listed 115 offers, including 52 coupon codes and nine free shipping promotions for back-to-school products.

Get student savings. Don’t forget to check for savings targeted specifically at students.

Through Sept. 18, Apple is offering education discounts on laptops, desktop computers and tablets. A 12-inch MacBook, which normally starts at $1,299, is $50 cheaper for college students or parents of college students (as well as faculty and staff at universities and K-12 schools). Apple is also throwing in a free pair of Beats headphones with eligible purchases.

Go tax-free. Many states have so-called tax-free weekends before the start of the school year. During these weekends, state sales tax is waived on qualified purchases.

To find out if and when your state will have a tax-free weekend, go to taxadmin.org (click on “2015 state sales tax holidays”).

Most tax-free periods for back-to-school shopping begin Aug. 7. In some states, including Massachusetts and Connecticut, the promotions start a week or two later.

Shop with a gift card. If you just graduated from high school and received gift cards as graduation presents, don’t forget to use them. According to estimates by CardHub, more than $45 billion in gift cards have gone unredeemed since 2005.

On the flipside, you can buy unwanted gift cards — for a discount — on websites such as giftcardgranny.com, and use the cards to make purchases at the related store.

In a recent search, Apple gift cards were available with discounts of as much as 4.28 percent. So a gift card with a value of $100 would cost $95.72. Buy several of those to apply toward a new computer, and the savings — on top of the student discount — really begin to add up.

Briefs Courtesy of Tribune News Service