NBME 15 to Step 2 CK conversion
Based on 410 real score reports that included a NBME 15 result. On average, students went on to score about 6 points higher on the real exam than on this form. Used alone, a NBME 15 score predicts the real result with a typical error of about ±6.0 points. Combining two or more tests is meaningfully more accurate.
Each dot is one real report: their NBME 15 result against the Step 2 CK score they went on to get. Hover or tap a dot to see that person's full test list. r = 0.71, n = 407.
| NBME 15 score | Predicted Step 2 CK |
|---|---|
| 220 | 238 |
| 225 | 242 |
| 230 | 245 |
| 235 | 248 |
| 240 | 251 |
| 245 | 254 |
| 250 | 257 |
| 255 | 260 |
| 260 | 263 |
| 265 | 266 |
| 270 | 269 |
| 275 | 273 |
| 280 | 276 |
Table and calculator assume the test was taken about 7 days before the exam, the typical timing in our data. Taking it closer to test day shifts the prediction; the full predictor uses your exact timing and every other test you have taken.
Common questions
Does NBME 15 underpredict your Step 2 score?
In real score reports, students scored about 6 points higher on the actual exam than on NBME 15, so the form runs conservative on average. The conversion above already corrects for this.
How accurate is NBME 15 alone at predicting Step 2?
A single NBME 15 score predicts the real result with a typical error of about ±6.0 points. Combining several practice tests is meaningfully more accurate, which is what the full predictor does.
Get a real prediction, not a rule of thumb
The full predictor combines all of your practice tests with their timing, shows calibrated probability ranges, and was the most accurate of every predictor we benchmarked against real scores. See the head-to-head comparison.