More Statistics on the MCAT – It’s Harder Than You Think

I’ve scoured the internet trying to find an authoritative source for relating MCAT scores to percentiles and have never been able to.  However, this afternoon I finally found some information on the shape of exam score distributions.  I then proceeded to blow way too much of my afternoon computing cumulative probability distributions.  My last post on MCAT statistics has been one of my most popular pages, so I figured I’d try it again.  Before I get into this one, I need to get two things out:

  • I absolutely hate the latest version of MS Excel.  This shouldn’t have taken more than about 20 minutes and it took me two hours instead because of how slow it runs on my Mac (and I have 8 GB of RAM!) and the fact that all of the normal functions have been made completely non-intuitive.
  • This little exercise confirmed for me that physicians should take calculus.

I’m going to try and see if I can find a way to upload an Excel sheet that has all of the calculations that I did.  I’ve included a table below that shows the relevant data and I’ve also shown the cumulative probability distributions for both the individual sections as well as the overall exam.

A few provisos:

  • I’ve assumed a normal distribution which may or may not be accurate.
  • Not every MCAT has the same statistics and these figures are based upon a sample size of one, so some variance is to be expected.
  • I’m not a statistician, so the perspectives and conclusions I drew from this might not be warranted by the data.

Here are cumulative probability functions for each of the 3 sections on the MCAT.  I ignored the writing sample.

Here’s the same quantity for the cumulative score.

A couple of observations to be made here:

  • Notice that about 20% of those taking the exam scored below an 18.  That means that 1 in 5 people that write the MCAT will wind up with a trio of 6’s or worse.  Ouch.
  • The magic score to get a person considered by an adcom is usually considered to be a 30.  This ends up being around an 80% score, which is just outside the first standard deviation for the exam.
  • Getting anything above a 35 is really hard.  To put this into perspective, only 50 people out of every 1,000 that take the exam will do this.
  • A final thing I noticed was the rarity of +37 scores.  There aren’t many at all, so this serves as really good evidence that you can’t believe anyone, particularly the student doctor forums.

I also noticed that the difficulty in moving a score from a 30 to a 35 seemed easier (a 15% difference) than moving from a 25 to a 30 (a 30% difference).  I’m not really sure what to attribute that to – it might have to do with the fact that individuals at that range may only differ by a couple of incorrect answers or that there are a lot fewer people left in that range.

Anyway, the end result that I got from this was that doing well on the MCAT is a lot harder than people seem to give it credit for.  My goal is a 35, but looking at these numbers, it’s easy to be discouraged.


21 Responses

  1. Discouragement is inevitable. But it is better to know and understand the lay of the land than be blissfully ignorant. What you do with the “WFT am I thinking” is the important part.

  2. You can find official stats in the MSAR.
    To be honest, I think they are just a lot of dumb people who never bother preparing. I’ve taken a handful of AAMC’s practice tests and scored >35, so I’m hopeful that I can hit a 35 on the actual test day.

    • good luck on test day, I did all the princeton exams and AAMC practice test and my lowest grade was a 26 on the hardets one. I was alway from a 28 to 36 which is an honest and normal standard deviation, I am a full lic and certified PE civil Eng. with MS in Water resources, so i have taken lots of boards and exams, and the real MCAT, at least the one on Sept 2012 was very hard, i got a 23, and I haven’t heard from higher scores from all the puerto ricans that took it with me or arround that date. Just 2 people got 28 and are goind to harvard already. It has gotten harder and harder, and will continue to get harder .

      Good luck to all !!!

  3. the single best piece of information regarding the infamous WAMC?!?! / MCAT / GPA freakout is the following AAMC table:

    There are some other tables that address race/ethnicity that are helpful.

  4. For me the difference (in studying/practice tests) between a 25 and a 30 came down to general content review and familiarity with the test. Going from a 30 to a 35 requires a lot more fine-tuning in terms of knowledge and test-taking skills.

  5. I agree with what Ryan said. 25 to 30 was just about remembering Physical Sciences. I think I got a 7 on that section on my first try. Going from a 30 to a 35+ was about realizing that I *could* improve my verbal score with practice. I improved by 5 points on that section also.

    It’s all about taking test after full length test and being really fast at figuring out what kind of question they’re presenting you. Stamina. Being really fast at doing numbers in your head won’t hurt either, but that just ends of being a byproduct of practicing.

    Good luck! And don’t be discouraged. You will do fine. If you practice.

  6. It sounds like improvement is largely a function of practicing and doing the work. This might sound like a foolish question, but how is that so many people bomb the MCAT? A lot of people get < 24. How is it that this sort of thing happens?

  7. I met one girl who is taking the MCAT the same time as me, and she doesn’t even know what the different sections of the test are. She seemed surprised when I told her there was a fair bit of chemistry on it. Seems like that kind of under preparation would mess up a score.

    I’ve noticed that a lot of people complain about verbal. If you are a well rounded person with decent critical thinking skills verbal should be easy. But a lot of these very left-brained science majors have forgotten how to read a piece like that and struggle. Also, like OMDG said, the timing takes practice. It took me a while to get used to doing the math problems quickly without a calculator. Lots of people don’t realize that a calculator isn’t allowed, since they’ve been using them forever, and are very unprepared that way as well.

  8. 30 is just about the score that one don’t need to think much but need to remember most of the points. I guess that’s why it’s also the minimum score that makes one likely to be accepted.

    However, I choose to believe all the 39+ around me. One girl got 45. They are rare statistically, but there should be a fairly decent absolute number

  9. Verbal has an *insane* curve, at least on the practice AAMCs. In the 77-question versions, missing just 5 will drop you to a 12 or 13. On the 52-question variant, missing 4 is enough to get you a 11 and lose 4 full points.

    I went from averaging 9s to averaging 11-12 on the practice tests after just doing so. many. passages. A good deal of the VR questions I missed was stamina and just wanting to get it over with (finishing the section with 30 minutes to spare…)

  10. Just so you guys know, a 35 is the best score you can get. Sure you can get a 39, but every medical school knows the difference between a 35 and a 39 is luck and little more. You can move from a 35 to a 40 on some MCAT’s by getting 5 more questions correct on the entire test. Plain and simple, its just luck at that point. You got lucky that you got questions you knew and got the ones right that you guessed on, but it doesn’t provide evidence of more capability at this point. That’s why nearly every medical school puts everyone over a 35 in the “35+ category” and doesn’t look at a 38 any differently then a 35. A side note, if you do get in the 43-45 range you will be looked at differently. Instead of the easy interview you would have gotten with a 38, your interview will be very long. The interviewers will be testing your personal skills very heavily because most people who score in that range wouldn’t feel comfortable talking to their stuffed animals, much less, a patient. A score of a 44 is not luck, it usually means you know everything. While it is luck whether you get a 35 or a 39, at the point of a 44, it means you knew everything because the test is created and scored so you can’t get lucky at hit a 44 instead of your usual 35 (they do this by making it statistically unlikely to score a 44 even if you knew everything about the known universe.) If you took a very long and timed addition test, you’d probably miss 1 or 2 despite having not difficulty with the questions. You do this on the MCAT and you are at a 43. They don’t want anyone to get a 45, and no one will. There are not enough people taking the test with the understanding of all MCAT concepts like we all know addition, to even make it likely that any of them would score a 45 despite knowing everything. The amount of random information you need to have in your head to get a 44 is indicative of doing nothing but studying since the age of 10, and the admins will want to confirm that this is not the case and you actually have spent some time out of the library.

    • In reply to the above, there’s really not that much material on the MCAT, say, as compared to the USMLE step exams. And you can find out exactly what is on the test by going to the AAMC website. With a summer devoted mainly to studying the MCAT and practicing, and also being a good test taker, 44-45 should definitely be possible. I don’t see why someone who gets a perfect SAT score and who studies hard for the MCAT shouldn’t get a 44 or 45. Also, the difference between a 35 and a 39 can come down to spending a few days studying some concepts you didn’t understand at the time you scored the 35.

    • thanks for taking the time to make up such a long paragraph full of bullshit.

      some of the things you said might be true, but most of it seems to be pulled out of your ass without any proof to back it up.

  11. Is MCAT the only thing that matters for med school admission?
    Why is so much stress on the GPA when kids are coming from a wide variety of colleges? Is there a formula (that I can understand) combining GPA and MCAT that will be used to measure a med school applicant’s eligibility?

    • Getting into med school is benefitted by the state you come from and the college you attended. A 4.0 at an easy university coupled with a strong MCAT score is a good combo. Residing in a small population state ups your admission odds greatly.

    • As a reapplicant, I have the same question. I have 3.3 cGPA from an Ivy school with a 35 MCAT. Tons of research, one publication, community svc n job shadow. No II yet. Trying to understand the process. Any help will be appreciated

  12. I was suggested this blog by my cousin. I’m not sure whether this post is written by him
    as no one else know such detailed about my problem. You are amazing!

    • This post was not written by your cousin. None of the people commenting on this (or any other) thread know me and I don’t forward anyone I know personally to my blog. But thanks for reading.

  13. Hi Med School Odyssey,

    I noticed you commented recently… can you share with a curious reader (me) where your journey has taken you since you last blogged? I followed for quite a while, since I share some commonalities with your experiences (former professional numbers guy, similar MCAT score, career transitioner, etc). I know you can’t share details specifically, but I’d love to know how the app cycle went for you!

  14. I scored a 39 to 41 range in 1997. GPA didn’t matter much at those numbers. Also, visibly pissed off a few interviewers who always thought they were the very best at everything.

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