Step 1 Cutoffs

what were the average and sdev for the step 1 given this past summer?

It has been about 5 years since I took step one, but 242 seems high for the 85th percentile. I think when I took it 85th percentile (roughly one Standard Dev above the mean) was 235.

I took step I about a year ago and I got a 229 which correlated to a 93%, I hope that gives you guys an idea.

Your percentile will correspond with what other people got during the block of time (which I don't know how they break down) you took step I.

the 93 is not a percentile. This is a common misperception about USMLE scores! To get an idea of how you did compared with others, look at the Standard deviation ..if mean is 215 and SD is 10, then a score of 235 means you did better than 95% of those taking the exam (2 SD above mean). Likewise, a score of 195 (2 SD below mean) means only 5% of examinees did worse than you did. One standard deviation above/below mean covers about 68% of examinees. So with a mean of 215 and SD of 10, a score of 225 means you did better than 68% of examinees, but worse than 32%.

If you read your score report, it will tell you that the 2-digit number is not a percentile. But they give you the mean and standard deviation so you can get a sense of how your performance compares to others. It's a bell-shaped curve with normal distribution.

actually, to be a little more precise, doing 1 SD above the mean means you did better than 84% of the people taking the test. This is because the mean corresponds to doing better than 50% of the people, and 1 SD is 34% better than that (1 SD above and 1 SD below mean equals 68%, which is 34% above and 34% below mean). Likewise, if your score is 2 SDs better than the mean, you are in the top 2.5%, not 5%.

To complement all the good info above:

If you want to know percentile rank for a normal distribution (we have to assume the USMLE scores are close to normal... which is probably true), calculate a Z score.

Z = ((Your Score)-(Mean Score))/(Standard Deviation)

You can then look up the correlation between Z score and percentile in Z score tables like this one:



For example, If your score was 248, the mean was 215 and the standard deviation was 15, then:

Z=(248-215)/15 or Z=2.2

Based on the table, a Z of 2.2 corresponds to a percentile rank of 98.6%

And, as stated by those above, a Z score of 1 (1 standard deviation above the mean) corresponds to 84%, and a Z of 2 corresponds to 98%

Again, this assumes a normal distribution, but it should be close for the USMLE.

By the way, does anyone know to what the 2 digit score corresponds? I know that at least a few programs pay the most attention to this score (or so I've heard from a couple P.D.'s). Near as I could figure when I took the test, any one with a Z > ~ 1.5 got a 99, but that is based on a few conversations with a few people.

On my score report sheet from this past June, it lists the mean as 216, and the standard deviation as 24...so that makes 240 about the 85th percentile.