NBME 15 Score Conversion for Step 2 CK
Form 15 is one of the two newest CCSSA forms for Step 2 CK. Form 15 is preselected below: 75% correct is about 244.
Convert your Form 15 percent correct
Use the equated percent correct from your report, or count your own correct answers out of 200.
Your own percent correct. It can differ slightly from EPC, so the range is wider.
Estimated Step 2 CK score · NBME 15
244
Likely range 228–260
75% correct on NBME 15 estimates about 244 on the Step 2 CK scale.
- Passing standard (218)
- Whole range is above passing
- 2026 national percentile of 244
- 30th percentile
- Input used
- Self-counted percent · 75%
Independent NBMEcalc estimate built from two reference points in NBME's published sample CCSSA report. It is not an official NBME conversion. If your score report already shows a Total CCSSA Score, that number is NBME's own Step 2 CK estimate — use it directly.
Already have your Total CCSSA Score?
The three-digit score on your Form 15 report is NBME's own estimate of your Step 2 CK score. Enter it here to keep it as the midpoint and get a planning range, or add other practice tests for a combined estimate.
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Where Form 15 fits
Form 15 sits just before Form 16 in NBME's current CCSSA set. NBME has not published a form-specific note for it; like every CCSSA it has 200 questions in four 50-question sections and reports a Total CCSSA Score on the same 1–300 scale as Step 2 CK.
A common plan is to take Form 15 two to three weeks before the exam and Form 16 in the final week, so the two newest forms bracket the last stretch of study. NBME's reports put each score's likely range at about ±8 points, so two results within that distance agree.
If Form 15 and Form 16 differ by more than about 8 points, treat that as a reason to take one more form rather than picking the number you like better.
NBME 15 conversion chart: percent to Step 2 CK
NBME equates every CCSSA form, so the same equated percent maps to the same estimate on Form 15 as on any other form. The likely range adds model uncertainty on top of the ±8-point range NBME prints on its reports, so it is wider than the report's own range.
| Percent correct (EPC) | Estimated Step 2 CK | Likely range | 2026 percentile |
|---|---|---|---|
| 60% | 206 | 194–218 | <1st |
| 64% | 216 | 204–228 | 2nd |
| 68% | 226 | 214–238 | 7th |
| 70% | 231 | 219–243 | 10th |
| 72% | 236 | 224–248 | 17th |
| 74% | 241 | 229–253 | 25th |
| 76% | 246 | 234–258 | 34th |
| 78% | 252 | 239–265 | 50th |
| 80% | 257 | 243–271 | 63rd |
| 84% | 267 | 251–283 | 87th |
Passing is 218 for exams administered on or after July 1, 2025. See the full 50–90% chart and how the curve is built on the NBME score conversion page.
NBME 15 FAQs
What should I enter for NBME 15 score conversion?+
If you have the three-digit Total CCSSA Score from your Form 15 report, enter it in the score calculator; it is already NBME's Step 2 CK estimate. If you have a percent correct, use the percent converter at the top of the page.
Is NBME 15 harder than NBME 16?+
Difficulty differences between forms are adjusted by equating, so a given equated percent correct converts to the same estimated score on Form 15 and Form 16. A form that feels harder does not, by itself, mean a lower Step 2 CK estimate.
What percent do I need on NBME 15 to pass Step 2 CK?+
The converter puts the 218 passing score at about 65% equated percent correct. Treat that as a rough line; the pass probability on your Form 15 report is the better guide.
What does 75% on NBME 15 convert to?+
About 244, with a planning range around it. Enter your exact percent in the converter above.
Is this an official NBME 15 conversion?+
No. NBME does not publish a percent-to-score table. The converter is anchored to NBME's official sample reports and is independent of NBME and USMLE.
Should I use NBME 15 by itself?+
A single form is a checkpoint. Pair it with a later form or UWSA 2 so you can see whether your results agree, and use the Step 2 CK score predictor to combine them.