How Is the Composite MCAT Scored?
The MCAT is scored on a scale from 472 to 528, with the median score being 500-501. Composite MCAT scores are calculated by adding up the scores of the four individual sections, which range from 118 to 132.
MCAT percentiles are updated every year on May 1st, so be sure to double check the AAMC website for the current percentiles. Keep in mind there is an overall trend of MCAT percentiles decreasing over time.
For example, a 509 was 82nd percentile in 2016, but it is now considered 77th percentile—meaning a 509 was a better score in 2016 than in 2019. This trend may affect your application process if you plan to apply to med school a year or more after you take the MCAT.
As of May 2019, the following are the benchmarks to pay the most attention to:
- 501: 51st percentile of all MCAT of all test-takers (i.e. the top half of test-takers)
- 505.6: 65th percentile (i.e. the median MCAT of all med school applicants)
- 511.2: 83rd percentile (i.e. the median MCAT of all med school matriculants)
- 514: 90th percentile
What Is the Scale for Each MCAT Section?
There are four sections on the MCAT:
- Chemical and Physical Foundations of Biological Systems (“Chem/Phys”)
- Critical Analysis and Reasoning Skills (“CARS”)
- Biological and Biochemical Foundations of Living Systems (“Bio/Biochem”)
- Psychological, Social, and Biological Foundations of Behavior (“Psyc/Soc”)
As stated above, each of the four MCAT sections are scored from 118 (1st percentile) to 132 (100th percentile). Scales vary per test. Below is a table of each of the four sections’ percentiles as of May 2019:
It is important to recognize that a score’s percentile varies by section. For example, a 125 on “Psyc/Soc” puts you at the 47th percentile, whereas a 125 on “CARS” puts you at the 60th percentile. Even though these have the same numerical score of 125, the “CARS” score is higher relative to other test-takers, as it is a higher percentile.
Looking at the table above, “CARS” is the hardest section to score well on, followed by “Chem/Phys,” “Bio/Biochem,” and finally “Psyc/Soc”—which is the easiest section to score well on as its percentiles are lower than the other sections’ for a given score.
While individual section percentiles are interesting, the section-by-section breakdown does not affect the composite score, as long as the sum of the sections does not change. For example, scoring a CP 124 / CARS 126 / BBC 130 / PS 130 and scoring a CP 127 / CARS 128 / BBC 127 / PS 128 both would give you the same composite score of 510, despite having different score distributions and associated section score percentiles.
Medical schools may be more concerned with the composite MCAT score or they might prefer to focus on individual section scores. Because of this, earning both a high composite score and solidly high scores across sections (i.e. no one score drastically below any others) is ideal. For information on how to best study for the MCAT, check out this article.
How Is Each MCAT Section Scored?
Your raw (i.e. un-scaled) MCAT section score arises from the number of questions you answered correctly, as incorrect and unanswered questions are graded as the same. For example, a raw score for Chem/Phys would be 44 if you answered 44 out of the 59 questions correctly.
Your scaled score (118-132) depends on the scale for the exact MCAT you take. The AAMC designates specific ranges of raw scores to correspond to scaled scores as a measure to preserve percentiles as much as possible. Therefore, a raw score of 44 on a particularly hard test (on which students miss more questions) could correspond to a 129, whereas a raw score of 44 on an easier test (on which students miss fewer questions) could correspond to a 127.
An extremely rough estimate is that one point off on a section corresponds to three questions missed on the non-CARS sections or two questions missed on CARS. This can be helpful in trying to make predictions on how a raw score relates to a scaled score. But, again, the scale varies greatly from test to test.
Unlike other computer-based tests like the GRE, the MCAT does not instantly provide you with your scaled score. Instead, the AAMC processes data of each MCAT’s submitted scores to designate which ranges of raw scores correspond to scaled scores in an attempt to best preserve current percentiles. This process is why MCAT scores take 30-35 days to be released. It’s a lot to process.
What the Heck Are Confidence Bands?
The MCAT’s emphasis on scaling rather than raw performance creates opportunity for a scale to help or hurt someone, meaning that scores may not be 100% reflective of a test-taker’s true abilities. To account for this, the AAMC includes confidence bands for one’s section scores and composite score.
For sections, the confidence bands are plus or minus one point from a test-taker’s official score. For example, a score of 126 on a section would have a confidence interval of 125-127. The confidence band for one’s composite score would be plus or minus two points from the official scores. Thus, a composite score of 510 would have a confidence interval of 508 and 512.
Basically, the confidence intervals are there to show that the AAMC recognizes that its grading scale is imperfect, but the intervals have no effect whatsoever on your admission to medical school. It is totally fine to just ignore them.
How Do You Make Sense of Your MCAT Score?
In a nutshell, the number of questions you miss on the MCAT is far less important than how other test-takers are scoring. What is much more important than how your MCAT is scored is how you actually score. The definition of a good score varies based on your med school goals, so be sure to do research on the admitted students’ MCAT score range for the med schools you care the most about.