Here’s one way to help ensure your student debt doesn’t balloon out of control: Get 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. That doesn't include students who take time off.

In fact, the Department of Education now 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 are able to graduate.

Why are kids taking longer to graduate?  “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, Oregon. “Students can really struggle to navigate that.”

Some students also take longer because they change majors or transfer schools while in college. Others delay taking the classes they need to graduate because there is more competition to get into them.

Of course, the longer you stay at college, the more student debt you take on. And with the cost of college so steep, the financial burden is much greater than in the past.

The average annual cost of tuition and fees at a public university is now more than $9,000, up from over $5,000 ten years ago. At a private college, the average cost is now more than $33,000, up from nearly $21,000 a decade ago. So if you borrow to pay for college, every extra year can increase your student debt significantly.

A number of schools around the country have launched programs to help students graduate in four years.

At the University of Buffalo, 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 that they can complete it.

Boise State has a similar program. At the California State University System, its Finish In Four Scholars program gives students more intensive counseling and a revamped online registration system to keep students on track with required courses.

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 Your School's Graduation Rate

If you’re deciding which college to attend or you are thinking about transferring schools, check the school’s 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 colleges, where 53 percent of students aiming for a bachelor's degree graduate in four years. 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 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 Carleton College, Georgetown University, University of Notre Dame, Columbia University, Pomona College, Washington University in St. Louis, and Davidson College in North Carolina.

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, so meet with an academic adviser. Also get to know the faculty in the departments where you want to take classes and ask for advice about the best classes to take from students who are further along in your 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 you have to take only 12 credits to be considered full-time.

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 individual 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 University of Hawaii, are using “banded tuition” which ensures that taking 15 credits a semester is the same cost as the 12-credit standard.

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 advisor 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.