Here’s one way to help ensure that your student debt doesn’t balloon out of control: Finish your college degree in four years.

Taking the traditional amount of time to earn a bachelor's degree is less common than you might think. Only 39 percent of full-time students pursuing a bachelor's degree finish in four years, according to the National Center for Education Statistics.

The Department of Education uses six years as the standard measure for completing a bachelor’s degree on time. But even after six years, only 60 percent of first-time, full-time undergrads who pursue a bachelor’s degree at a four-year institution complete their degree.

Why are kids taking longer to graduate? For some, it's a big change to be in charge of all of the classes they need to take. “Many students are thrown because they go from a very structured environment in high school to enormous freedom in college,” says Ian Fisher, director of educational counseling at College Coach and a former college admission counselor at Reed College in Portland, Ore. “Students can really struggle to navigate that.”

Some students take longer because they change majors or transfer schools while in college. Others can’t get the courses they need to graduate on time because there's competition to get into those classes.  

Of course, the longer you stay in college, the more student debt you take on if you need to borrow to pay for school. And with the cost of college so steep, the financial burden is much greater than in the past.

More on Paying For College

The average annual cost of tuition and fees at a public university was $9,970 for the 2017-2018 school year, up from $7,280 10 years ago. At a private college, the average cost is $34,740 a year, up from $27,520 a decade ago. Including room and board, the cost of going to a public university is $21,000 a year and a private college is $47,000. So if you take out loans to help pay for college, each extra year can increase your student debt significantly.

A number of schools across the U.S. have launched programs to help students graduate in four years.

At the University of Buffalo, for example, students enrolled in its Finish in Four program can get guidance and resources from the school to help them achieve that goal. For students who fulfill the obligations of the program but still can’t graduate in four years, perhaps because they are double majoring, the university picks up the tuition and fees so they can complete it.

Boise State has a similar program. The California State University system's Finish In Four Scholars program gives students more intensive counseling and a revamped online registration system to keep students on track with required courses.

But even at schools that provide extra help, it's easy to fall behind. If you’re heading to college next year or are in college now, here’s an action plan you can use to help you graduate in a timely way. 

Check Graduation Rates

If you’re deciding which college to attend or you're thinking about transferring schools, check the four-year graduation rate. Every school has to report those stats, which you can find at the Department of Education’s College Scorecard site.

Graduation rates tend to be higher at private nonprofit colleges, where 53 percent of students aiming for a bachelor's degree graduate in four years, especially at those that have more selective admission rates.

Among public universities, only 50 of the more than 580 public four-year institutions in the U.S. have on-time graduation rates at or above 50 percent for their first-time full-time students, according to nonprofit advocacy group Complete College America.

A college with a high graduation rate indicates that it provides a lot of support to its students, Fisher says. According to U.S. News & World Report’s annual ranking of colleges with the highest graduation rates, more than 90 percent of students graduate in four years at the Juilliard School, Bowdoin College, College of the Holy Cross, Amherst College, Babson College, Georgetown University, Hamilton College, and the U.S. Naval Academy.

Complete Required Classes Early

To graduate in four years, figure out the courses you’ll need every semester in the major you’re pursuing. It can be confusing, and courses can be difficult to get into, so meet with an academic adviser regularly for help. Get to know the faculty in the departments where you want to take classes, and ask for advice from students who are further along in the same program. 

About 80 percent of college students change their major at least once, according to the National Center for Education Statistics. Some schools make you declare a major by the end of your first or second year. If you’re not sure what you want to study, hedge your bets by taking the general education requirements you need to graduate as well as classes in the major you want to pursue.

In your first two years of college, don’t take any classes that don’t fulfill some graduation requirement, Fisher advises.

Take a Full Course Load

To get a four-year degree at most schools, you need to earn 120 credits. That’s 15 credits per semester, or 30 credits per year. Only half of students at four-year schools take 15 or more credits a semester, according to Complete College America. One reason is that students have to take only 12 credits to be considered full-time and be eligible to receive some forms of financial aid.

Taking 15 credits each semester sets you up for success: 79 percent of students who take 30 or more credits in their freshman year graduate on time vs. 37 percent of those who take 12 to 24 credits in the first year. 

About 15 states and a number of colleges have signed on to a Complete College America initiative called 15 to Finish, which encourages students to take 15 credit hours per semester.  Some schools, such as the University of Hawaii, are using “banded tuition,” which ensures that taking 15 credits a semester is the same cost as the 12-credit standard.

Get the Classes You Need

At some schools, classes fill up fast. Put registration deadlines on your calendar. If you can’t get a course you need, the registrar’s office isn’t likely to help you get in, especially if it has dozens of other students in the same position as you. Instead, take your case directly to a course instructor or enlist someone you know on the faculty or staff, or an adviser who can advocate on your behalf.

It’s never too late to get back on track. If you’re behind, check whether you can make up classes with summer courses or take courses during your school’s winter break. You could also take classes at a community college or online, but first make sure your school will accept the credits.

If you manage your classes well, you may even graduate early. And that could save you even more money.