What Does Student-to-Faculty Ratio Really Mean?

What Does Student-to-Faculty Ratio Really Mean?
portrait of Mark J. Drozdowski, Ed.D.
By Mark J. Drozdowski, Ed.D.

Published on August 10, 2021

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On a beautiful morning in sun-soaked Pasadena, you make your way down San Pasqual Walk toward Linde Hall, full of nervous anticipation. It's your first day of classes at Caltech.

You glance once again at your schedule. "Math 110, MWF 9:00" it says.

As you walk toward your destination, you wonder which two students will be your classmates. Someone from your dorm, maybe?

As you enter the auditorium, you encounter about 80 other eager faces. Wait, you think. Didn't I read that Caltech boasts a student-to-faculty ratio of 3-to-1? Doesn't that mean there's one faculty member for every three students? What's with all these people?

Ah, but you should know better. You're a bright kid, after all — you're at Caltech. You should know student-faculty ratios shouldn't be taken literally.

Student-Faculty Ratio and Class Size Are Different

Yes, Caltech does have a student-faculty ratio of roughly 3-to-1, one of the lowest in the nation. And yes, that does technically mean there's one faculty member for every three students. But it most definitely does not mean you should expect to have classes with just two other students.

Take a closer look at Caltech's stats and you'll see about 69% of its classes feature fewer than 20 students. Another 23.3% have between 20 and 49, and 7.6% have 50 or more.

That introductory mathematics course, a first-year class with 80 or so students, might be an outlier, but it does reveal a fundamental truth about student-faculty ratios: They do not always equate to class size.

It's easy to find student-faculty ratios. Colleges report them through the Common Data Set, and they're published each year in the U.S. News & World Report rankings.

It's not so easy to find average class size. The Common Data Set does reveal class sizes by range: 2-9, 10-19, and so forth, up to 100 and above. But nowhere does it mention the overall average or median. And colleges typically don't share that stat.

Harvard, for one, does. On its website, Harvard notes a student-faculty ratio of 5-to-1 and a median class size of 12. Of the nearly 1,300 courses the College offered last year, more than 1,000 of them enrolled 20 or fewer students.

How Is a Student-Faculty Ratio Calculated?

That "20" figure is a magical number because it's how U.S. News evaluates class size. In its formula, "class size index" counts for 8% of the overall ranking and is the most highly weighted faculty resource measure.

Colleges get the most credit for classes with fewer than 20 students. They get less credit for classes with 20 to 29, even less for those with 30 to 39, and less still for those with 40-49. Classes over 50 get zero.

Their point is, simply, that smaller is better.

Some institutions, such as Northeastern University, have reportedly tried to "game" the rankings by adjusting their operations to meet U.S. News' criteria. One tactic is to cap as many courses as possible at 19 students.

U.S. News also factors in student-faculty ratio as 1% of the overall ranking. The magazine is quite specific about who can and cannot be counted, following the Common Data Set's guidelines. As with class size, a smaller ratio is better.

Keep in mind we're including only undergraduates and the faculty who teach them. Graduate students and faculty who teach only at the graduate and professional-school level are excluded from these calculations.

The formula is fairly straightforward. I won't display it as a mathematical computation because those give me a headache. (I'm not Caltech material.)

Basically, it's an attempt to calculate full-time equivalents for both students and faculty to create an accurate ratio.

It's also a way to account for the various types of faculty and their teaching loads. Some research faculty don't teach at all. Some full-time faculty teach only part time. And then there are adjunct faculty who teach a range of credit hours term to term.

If you included all the faculty in the ratio as a headcount, the numbers would skew far too low. Heck, Caltech could have more faculty than students.

However, faculty numbers do include some administrators who teach part time, along with professors who are on sabbatical. So faculty who aren't even on campus are counted in the equation. Go figure.

What's a Good Student-Faculty Ratio?

According to the National Center for Education Statistics, the national average for student-faculty ratios was 14-to-1 in fall 2018. Ratios at top-ranked schools in U.S. News' list tend to be lower than that, largely because the undergraduate enrollments are smaller.

UCLA (ranked No. 20 on the list) has roughly 31,500 undergrads, with a student-to-faculty ratio of 18-to-1. Top-ranked Princeton, with about 5,400 undergraduates, has a ratio of 5-to-1. MIT (ranked No. 4) enrolls 4,530 undergraduates with a 3-to-1 ratio, and Caltech (ranked No. 9) also has a 3-to-1 ratio with 938 students.

At the higher end of the continuum lies the University of Central Florida (ranked No. 160) with a ratio of 30-to-1, though about 27% of its classes have fewer than 20 students. Of course, UCF has a whopping 61,456 undergrads, making it roughly 65 times larger than Caltech.

Should You Care About Student-Faculty Ratios?

Now you know why you can't take student-faculty ratios literally. They have some bearing on educational quality, enough to make U.S. News pay attention. Yet the magazine pays far greater attention to actual class size, a more useful indicator of what the educational experience is like.

Should you care about these ratios? It depends on your preferences. Smaller ratios generally suggest smaller class sizes.

If you value close contact with professors and a more interactive learning environment, then smaller will definitely seem better. If you don't mind being a face in the crowd in larger classes, then it probably doesn't matter as much.

That said, don't assume a large university won't offer some smaller classes. If you're a philosophy major at UCF, which in a recent year awarded only 23 bachelor's degrees in that concentration, you might feel as though you're at nearby Rollins College, with its 11-to-1 ratio.

Many large institutions also feature honors colleges and programs that replicate the small-college experience with seminars, close interaction with professors, independent study, and research opportunities with faculty mentors. You can find ways to make large schools seem small, and vice versa.

Everyone has a different educational experience, even within the same institution. Class size can vary dramatically from major to major and course to course. As you advance in your major as a junior or senior, your classes most likely will get smaller.

So enjoy your math class and its veritable sea of humanity. You may not encounter many more like it.


Feature Image: Tom Werner / Photodisc / Getty Images

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