March 30, 2011

High School GPA versus College Success

A while back I stated my opinion that you shouldn't bother going to college if you can't at least get B's in high school.   I still stand by that generalization.   If the best you can do is barely squeaking by as 'average' in high school then you'll very likely struggle to pass in college.    If you were below average in high school, I think that rather than jumping into college you'd be better off finding employment and working for a year, going to a skilled trade, possibly joining the military or simply taking some time to decide what is best for your future.   Of course there are exceptions and a small portion of students who do poorly in high school may go on to achieve success in college.   There were a couple replies to that original article from people who disagreed with me because they were poor students in high school but were able to succeed in college.

Am I right in making a generalization that most C high school students struggle in college?  It seemed to me a fairly safe assumption that if you struggle in high school you'll struggle even more in college.  Sometimes though such assumptions can turn out to be false so it is best to look at actual data to validate the idea.  Today I'll dig into that data a little more to explore the correlation between grades in high school and students success in college.

Today's C is the new D
First off lets start out with some perspective of what a C average in high school actually means today.  C grades in high school are typically not 'average' as they may have been thought of in the past.  The vast majority of college freshmen got A's and B's in high school.  According to census data on college freshmen almost half (48%) of the students entering college had high school GPA's in the A- to A+ range.   That would mean the median high school GPA for college freshman is around 3.4 to 3.5 range give or take.    Another 47% of students had high school GPA's in the B- to B+ range.   Only 4.5% of entering college freshmen in 2009 had high school grades of C or lower. By comparison 30 yeas ago in 1980 about 15% of entering freshmen had C or worse high school grades.

First a study tying high school grades to college success

I found a report titled Predicting Different Levels of Academic Success in College Using High School GPA and ACT Composite Score. ACT Research Report Series  that looked at the correlation between GPAs received in high school by students and the college GPAs achieved by the those same students.   They looked at over 200,000 students and tracked their grades in college and compared them to their high school GPAs.  Theres a fairly good correlation between high school GPA and college GPA.

For students with high school GPA's of 2.0 the probability of getting a college GPA of 2.0 or better is about 0.5, so around half the C students  in high school do better or worse than C in college.   The probability of C students getting a 2.5 or better in college drops to 0.2 and the probability of 3.0 in college is down to just 0.05.   To put that another way 95% of students who got C averages in high school do not achieve B average or better in college.   Keep in mind that this is any and all colleges so we're not talking about Harvard.   We're talking about getting B's in any college in general.    Of course there are exceptions and about 5% of the C students in high school go on to get B or A grades in college.

Figure 2 in the report on page 17 is a graph showing the relationship between high school GPA and college GPAs.   Here is that same data in table form :

High School GPAs
College GPA 2.0 2.5 3.0 3.5 4.0
2.0 or better 0.50 0.65 0.75 0.90 0.95
2.5 or better  0.20 0.40 0.60 0.75 0.85
3.0 or better 0.05 0.15 0.30 0.50 0.75
3.25 or better 0.01 0.05 0.13 0.30 0.60
3.5 or better 0.01 0.02 0.08 0.20 0.47
3.75 or better 0.01 0.01 0.01 0.08 0.30

The columns are the high school GPA obtained and the numbers are the probability of achieving the college GPA for each row.  For example if you look at the top and find the column for 3.5 high school GPA then the chances of getting each of the college GPAs on the far left are given by the numbers.   They have a 0.90 chance of getting over 2.0 in college, 0.75 of 2.5 or better, 0.5 probability for 3.0 or better college grades etc.

Second study from Back in "the olden days"

I also found a smaller paper from 1958 titled the Correlation of High School and College Grades t from the American Journal of Physics that looked at the correlation between high school grades in math and science and the grades in college.   Table 2 in that paper presents the relationship between high school grades in math and the first year math course grades in college for 238 students:

College math grade
High school grades below 2.0 2.0 to 2.4 2.5 to 4.0
A 17% 14% 69%
B 37% 25% 38%
C or D 71% 13% 16%

You can see a high correlation between high school grades and college grades.  Most students who got C's or D's in high school went on to get C's and D's in college.   However you can see that theres still 16% of the students who had C or lower in high school but ended up with B or A grades in college.     Only 12% of the students in the sample had A grades in high school while 40% had B's and 48% got C's or D's.    In this group at least back in 1958 the C grade was more of a true average or median grade with about half students getting above C and about half getting C or lower.   If you took that group of students from 1958 and put them in a school today I would expect that many of the kids getting C's back in the 50's would be getting B's or even A's today. This is an important detail that we should keep in mind that grade inflation has made a C grade level today far worse than what a C from decades past represented.   

One More Study on the Topic

I also found the article with the lengthy title of  "VALIDITY OF HIGH-SCHOOL GRADES IN PREDICTING STUDENT SUCCESS BEYOND THE FRESHMAN YEAR: High-School Record vs. Standardized Tests as Indicators of Four-Year College Outcomes"   (via google)   That one is from the University of California system study of about 80,000 students.  

It says pretty bluntly :

The study finds that high-school grade point average (HSGPA) is consistently the best predictor not only of freshman grades in college, the outcome indicator most often employed in predictive-validity studies, but of four-year college outcomes as well.

However I should point out that the U.C. system is pretty selective and most of the students admitted are in the top 10% or so of the graduates in California.   It doesn't really relate to 'C' students since they can't usually get into U.C. schools.   I do think though that their general conclusion that high school grades are a good predictor of college success is useful to see.

Bottom Line : The data I found confirms my belief that a C student in high school today has a very low chance of obtaining good grades in college. 


  1. My high school GPA was 3.8+ and my college graduation GPA was 3.0. I did do mechanical and aerospace engineering though. All the other stuff was the easy part.

  2. Ryan you make a good point. What you major in in college will certainly have a big impact on your grades. You can also say that the difficulty level of the high school also impacts the high school grades. For example a student who gets C's in an elite private high school then goes to a non competitive state college and majors a relatively easy major might get A's in college.

    The numbers in the studies talk about students in general. They don't split out the kids who went to 'easy' high schools or took all the hard classes in high school and
    they don't differentiate between someone going to a elite college and majoring in pre-med versus someone going to north by northwest state university of rural somewhere and majoring in finger painting.

    I think its quite possible that C students in high school are usually only admitted to the easier colleges and then gravitate towards the easy majors.

  3. Im a high school student, freshman and I have to say... I disagree, there are some of us who education comes easy to. A teacher teaches it once and the student automatically understand it. Lucky! Then they're are the students that have to work hard to learn! One simple example won't work for the student who know it. Sometimes it takes notes, more than one example, a teachers explanation, a students explanation to understand one problem! Thats I'm the students who I need a teachers explanation, a students explanation to understand one problem and I have to work my ass off to understand and my friends are just so extra smart! They're the types of people who get it once the teacher explains it and they have lower grades than I do, they don't even try and I predict that Im going to be rolling in money before they are! So it all depends on the person whether they chose to do well or don't.

  4. Natalia: I agree with everything you said. It certainly does all depend on the person.

    Everything I'm reporting here is about statistical averages for a large group of people. The vast majority of below average grade students in high school will not do well in college. But that doesn't say anything about a motivated individual.

    Highly motivated individuals who don't do well in high school can certainly achieve in college. On the opposite end an unmotivated A+ high school student can fail in college.
    But most of the time the poor high school students will do poorly in college. It just gets harder. Very few students are motivated well enough to turn themselves around and hard enough extra to achieve good grades in college after doing poorly in high school. Most of the students who get poor grades in high school are not highly motivated and won't get good grades in college.

    Kudos to anyone who turns their life around and does great in college after doing poorly in high school. But I'm not betting on high school students with C averages to get A's in college.


  5. There are so many other factors involved in true success. My highschool GPA was not great, maybe a 2.5 if that. However, I have 2 college degrees! My college GPA was 3.7, with a 4.0 in my Finance classes but even with that not one employer asked my GPA nor did they care. The degree is all that counts. Maturity that is gained between ages 17-21 and your work ethic/determination has more to do with success than your highschool GPA.

  6. I received a high school GPA of 2.4. But after high school ended I developed a very strong work ethic as well as the interest and want to learn. I went to community college and transferred to a 4 year University ending with a college GPA of 3.7 and just got into graduate school for physical therapy! So I have to agree with the person who said "maturity is gained between ages 17-21", I couldn't agree more! I've grown into this wonderful, smarter, and hard working person. Anybody can be or do anything they want to achieve.

  7. I actually graduated HS with a 2.7 and I just completed my first semester of college with a 3.5 and an A average in college algebra when I bombed HS maths. Allot of it has to do with a students state of mind and work ethic. High school for me and allot of my peers was a time to party and not give a fu** but when I got to college "shit got real" and everything soon came into perspective that I have to get my life together. Also that no one forces anyone to go to college, thus it is a serious and expensive environment:don't F up... Point being-all these studies and tests really do not prove anything.Oh yea, my ACT math score was a 17 which is an F but I went on to get an A (98) in college Algebra.. Any student who studies with determination can achieve beyond their expectations or what any study or standardized test attempts to predict.

  8. Well, I had a 2.2 highschool gpa. I'm at 31 credits in college and have a 3.78 gpa. I had personal issues all throughout high school that I only began to resolve my senior year. All I cared about was fitting in and ended up just smoking a bunch of weed the entire time. With those issues cleared up I'm able to be the student I'm supposed to. College has actually been way easier than I expected it to be. Computer Science major by the way.

  9. I'm not sure I agree with this assumption either. My wife was a "C" student in High School but graduated with honors at a 3.96 Undergrad GPA and currently has a 3.90 with 4 classes left in her Graduate program.

  10. I did fairly okay in high school graduating with a 3.0 GPA and an weighted 3.1 because I took one AP class & two honors classes. My first semester of college I didn't do as I hoped. I was hoping to get a 3.0 but instead I got a 2.2 b/c I was majoring in the wrong major. Then, my GPA did go up to a 2.5 at the end of the year. However I still wasn't happy with it & I had to move & go to another college. I messed up again and got a 1.6 GPA. I was only taking 3 classes & made only one A. But anyways next semester I'm going back to taking a full load. Now, I actually know what I need to do instead of being lost and instructors not answering my questions clearly. I'm hoping to get a 3.8 so my overall GPA can get to a 3.3. So many factors can play into a students GPA. It doesn't always mean that if you do well in college you're gonna do well in life. Because my cousins are book smart but they don't have common sense....
    It really depends on the person and what they're studying and who's influencing them as well.

  11. Lots of people commenting think they're disproving the rule by being an exception. Keep in mind as you read this and disagree, the below average C students who this DOES apply to vastly outnumbers you, a single individual.. and they won't comment support of the validity of this analysis because it is inherently embarrassing. I 100% agree with the argument proposed and it has lots of empirical data backing it.


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