NBME % correct ↔ 3‑digit score

Q: How do I convert an NBME percent correct to a 3-digit score?

Pick your NBME form and enter your raw percent correct. The tool maps it to the 3-digit form score using a per-form conversion of about 2.2 points per percent, calibrated on real reports and blended with published conversions. You can also enter a 3-digit score to get the percent back.

Q: How accurate is the percent-to-score conversion?

On forms with enough data the leave-one-out error is about 2 to 3 points. The two newest forms have thinner data: NBME 15 is approximate and NBME 16 is preliminary.

Took an NBME form offline? Estimate the 3-digit score associated with your raw percent correct. The converter also works in reverse. Type in either box; the other updates, along with a predicted Step 2 CK score. Works for NBME 9 through 16.

NBME form

% correct

3-digit score

≈ — predicted on Step 2 CK

Calibrated on real reports listing both a percent and a 3-digit NBME 14 score, blended with published conversions (typically within about ±3 points).

Each form's predicted Step 2 assumes typical timing; the main predictor uses your exact timing and every other test. See each form's full breakdown: NBME 9 · NBME 10 · NBME 11 · NBME 12 · NBME 13 · NBME 14 · NBME 15 · NBME 16.

How the conversion works

When you take an NBME self-assessment online, NBME turns your raw performance into a 3-digit score with a fixed, form-specific scoring table. Offline takers only have a percent correct. This tool estimates the mapping with a shared slope of about 2.2 points per percent plus a form-specific difficulty adjustment. The estimate was fit to r/Step2 reports that listed both a percent and a 3-digit score, then blended with published conversions.

Common questions

How do I convert an NBME percent correct to a 3-digit score?

Pick your form and enter your raw percent correct. NBME Step 2 forms have 200 questions, so each is worth about half a percent. The tool maps your percent to the 3-digit form score (about 2.2 points per percent, calibrated on real reports and blended with published conversions), then to a predicted Step 2 CK score. You can also enter a 3-digit score to calculate the equivalent percent correct.

Why does the same percent give a different score on different forms?

Each NBME form has its own scoring curve, so a given percent maps to a slightly different 3-digit score depending on the form. The differences are small (usually within a couple of points), but the converter applies the specific curve for the form you select.

How accurate is the percent-to-score conversion?

On forms with enough data the leave-one-out error is about 2 to 3 points. Two newer forms have thinner data: NBME 15 is approximate and NBME 16 is preliminary (anchored to the recent forms).

Combine your scores

Combine your practice scores and test dates in the full predictor. Open the predictor →

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