Practice Exams
NBME Score Conversion: What Your Practice Score Means
How to read a Step 1 or Step 2 CK NBME self-assessment report: equated percent correct, the likely range, the probability of passing, and when you are really ready.
· 6 min read · IvyMed
The short version
- Step 1 NBME forms report an equated percent correct and a probability of passing, not a three-digit score
- Step 2 CK forms still give a three-digit estimate: compare it with the 218 passing standard
- Read the likely range, not the single number: repeat scores move about 4 points
- There is no official table that converts these scores, so treat any chart online as a guess
Read your NBME score
Type the number from your score report. Nothing is saved.
A reading of your report, not a prediction: NBME publishes no table that converts these scores, and the estimated probability of passing on your report is the number NBME stands behind.
Step 1: equated percent correct and probability of passing
Since Step 1 went pass/fail, the NBME Comprehensive Basic Science Self-Assessment (the Step 1 NBME forms) reports your score as an equated percent correct: roughly the share of the tested content you have mastered, adjusted so that a harder form and an easier form are comparable.
The report also gives an estimated probability of passing Step 1 if you tested within about a week. That probability is the number NBME stands behind. It is not the same as your percent correct: a 90% chance of passing still means about one in ten students at your level would not pass.
NBME shows an example low-pass range of roughly 61–67% equated percent correct. If your likely range touches that band, NBME says to be extra careful.
Step 2 CK: the three-digit estimate and the 218 standard
The NBME Comprehensive Clinical Science Self-Assessment (the Step 2 CK NBME forms) still reports a three-digit score: an estimate of what you would have scored on Step 2 CK that day. It also gives a probability of passing and your equated percent correct by content area.
Compare the three-digit estimate with the Step 2 CK passing standard, which has been 218 since July 1, 2025. Most students also want a target well above passing, because residency programs see the number.
Why there is no exact conversion chart
NBME does not publish a table that turns a percent correct into a Step score, and the probability model is updated every year. Charts that claim an exact conversion are someone’s estimate from self-reported scores.
What you can trust: your probability of passing, your likely range (scores repeat within about 4 points two-thirds of the time), and the trend across two or three recent forms taken under real conditions.
When you are ready to test
A good rule: two recent official forms in a row clearly above the low-pass range (Step 1) or clearly above your goal (Step 2 CK), taken timed and in one sitting, with the Free 120 in the final week landing where those forms say it should.
- Take forms in exam conditions: timed, full length, no pausing to look things up.
- Space them out: one form a week through dedicated, more in the last two weeks.
- Review every miss before the next form; the score only moves when the gaps close.
Questions students ask
- How do I convert my NBME score to a Step 1 result?
- You can’t exactly: Step 1 is pass/fail and NBME reports an equated percent correct with a probability of passing. Use the probability and whether your likely range sits above NBME’s example low-pass range of about 61–67%.
- What is a passing NBME score for Step 2 CK?
- Compare the three-digit estimate on your report with the Step 2 CK passing standard, 218 since July 1, 2025, and check the probability of passing NBME gives you.
- How accurate are NBME practice scores?
- NBME says a repeat score falls within about 4 points of the reported score two-thirds of the time, so read the likely range and look at your trend across several recent forms.
- Is there an official NBME score conversion chart?
- No. NBME does not publish one, and its probability model is updated each year. Online charts are estimates from self-reported scores.
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