You've calculated your college savings, loans and grant money, and have crunched the numbers to develop a workable budget. Now, how much was set aside for the occasional pizza?

"If a college student eats one pizza a week (off-campus), he'll have spent $2,000 on pizza by the time he graduates from a four-year program," says Mark Kantrowitz, publisher of FinAid.org, a resource for student financial aid.

That two grand probably wasn't accounted for when you were calculating your typical college costs. Most families plan their college expenses based on figures provided by the colleges and universities themselves, which are very loose estimates on a degree's cost and essentials such as transportation and textbooks.

"The College Board reports that in 2010-2011, students could expect to spend an average of $1,137 on textbooks and supplies. A new financial accounting textbook can cost $150 to $200," says Carole Walters of Flat World Knowledge, a publisher of free and open textbooks.

Graham Haskin, who graduated from Emerson College in Boston, says he was dismayed by the cost of textbooks, but the really big college expense came from using public transportation. "I took the T (subway) everywhere. The cost of the monthly pass or the cost of the per-trip rate was a surprise," Haskin says.

The website for the University of North Carolina at Wilmington estimates student transportation costs at $1,452 per year, whether a student lives on campus or commutes. Since some students commute to their campuses from as far away as 50 miles, it's good to keep in mind that individual college expenses will vary.

So That's Where Your Money Goes

Because not everyone can be like Rodney Dangerfield's rags-to-riches character, Thornton Melon, in "Back to School," students have to rely on traditional financial planning methods. This involves anticipating rising college costs. However, few can forecast the rates at which today's gas and grocery prices rise.

According to a College Board study, basic public college tuition alone has increased, "from 2000-01 to 2010-11 rang(ing) from 79% in the Middle States region to 161% in the West before adjusting for inflation." Add in unplanned college expenses, and many who think they're prepared are in for wallet shock.

"The dorm and dining hall provide the basics, but students will need everything from laundry money to shaving cream and probably cell service," says Greg Karp, author of several books on personal finance. Students agree and, although some college costs are predictable, others sneak up on them.

Luke Mayberry, a drummer and music major at East Carolina University, in Greenville, N.C., says carrying a major like his costs extra bucks. "I was definitely surprised by how much money I was spending on sheet music and mallets/drumsticks outside of the required materials list I'd been given during the summer."

Mayberry says he spent about $500 extra on equipment and sheet music at the beginning of his first semester. And music majors aren't the only ones: Art and graphic design majors, for example, must often purchase expensive software as well as materials.

Kantrowitz adds that in some states, such as Florida, universities tack on an additional charge once a major is declared. "Those fees aren't necessarily planned for," he says.

A Few (Expensive) Things to Consider

After budgeting for the dorm or apartment, shelling out for a meal plan, paying tuition, activity and insurance fees, experts say you should plan for an additional $300 to $400 out of pocket each month to cover day-to-day extras. Here are some of the culprits most likely to drain your bank account.

Parking: Most universities charge to park on campus, even for dorm-based students. Expect to pay upward of $500 for two semesters of parking privileges at most major universities; less at community colleges and rural schools. And watch those parking tickets: An illegal five-minute parking job can end up costing anywhere from $2 (a no-parking zone at Brandeis University) to $75 (a handicapped parking ticket at Vassar College) in fines.

Sororities and fraternities: If your student pledges, then he or she (or you) will be on the hook for upward of $2,000 in fees and other Greek-associated expenses over the course of a college career. The University of Southern Mississippi at Hattiesburg estimates the average total new member cost for the first two semesters at $1,050.

Hidden apartment costs: Opting out of the dorm can be expensive in ways you might not realize. Most campus-style apartment complexes require 12-month leases, so you or your child will be paying for the summer months, even if he or she isn't enrolled in school. If you sublet, benefit from Haskin's unfortunate experience: He sublet his share of a home without a contract. When the renter didn't pay and trashed the place, "I had no recourse. If you're subletting, get a contract," he says.

Laundry: Mom won't be doing it anymore. If your kid has to pay to wash clothes, the costs of detergent and dryer sheets, as well as several bucks a load to use a community washer and dryer, will add up. Don't laugh -- doing two loads a week at approximately $3 per load (not including the price of detergent) could run college expenses up by more than $200 a year. It will cost even more if a student leaves his or her clothes unattended and someone walks away with them -- an unfortunate but not uncommon occurrence.

Computer malfunctions: As soon as the warranty on your student's laptop tanks, so will it -- or at least it seems that way. If available, buying a computer through the college can be a potential route to take. While it can cost a bit more, the college often offers free or reduced tech support, which can help cut college costs and reduce long-distance parental anxiety. Laptop rental may also be an option, so check in with the university to find out if this is an option.

Unless your student is comfortable handling personal finances, resist the temptation to plunk a semester's spending money on a debit card and trust it will last. Kantrowitz says that it's best to start releasing your hold on your child's funds gradually. Otherwise, you may find the money you earmarked for a bus pass has paid for a new iPod. And that's one unexpected college expense that you can head off at the pass.