Estimated range
The lower and upper bounds make normal form and model uncertainty visible.
NBME Score Calculator for Step 1 & Step 2 CK
Enter wrong answers or percent correct to estimate a practical NBME score range. Use the result for study planning, then verify it with your official NBME self-assessment report.
Step 1 readinessStep 2 CK estimateNo sign-upPrivate on this device
Free NBME score conversion calculator
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How does the NBME score calculator work?
The calculator turns one 200-question self-assessment into a transparent planning range. You choose the exam and form, enter wrong answers or percent correct, and get an educational estimate with its limitations kept visible.
- You choose: Step 1 or Step 2 CK and the specific NBME form.
- You enter: wrong answers out of 200 or your percent correct.
- You get: an estimated range and readiness explanation—not an official score.
Supported NBME forms and outputs
Choose the form you actually completed. Step 1 and Step 2 CK stay separate so each result uses the right output and readiness context.
| Feature | Step 1 | Step 2 CK |
|---|---|---|
| Supported forms | NBME 25–31 | NBME 9–16 |
| Questions | 200 | 200 |
| Inputs | Wrong answers or percent correct | Wrong answers or percent correct |
| Output | EPC-style readiness range | Estimated three-digit range |
| Official context | Step 1 is reported Pass/Fail | Current passing score: 218 |
Understand your NBME score estimate
Use the range and your recent trend to plan the next study step. A single central number is intentionally not presented as certainty.
Readiness zone
Step 1 uses EPC-style readiness; Step 2 CK compares the estimate with 218.
Trend over time
Consistent movement across recent official reports matters more than one result.
How to use the calculator
- 1
Choose the exam and form
Select Step 1 or Step 2 CK, then choose the exact NBME form you completed.
- 2
Enter your performance
Use wrong answers out of 200 or percent correct. Both inputs produce the same underlying percentage.
- 3
Read the range, not a promise
Compare the estimate with your official report and your trend across multiple assessments.
Keep the estimate in context
Official NBME reports are primary. Raw-to-score curves are community-derived estimates, and one result should not decide an exam date. Compare multiple assessments and use school or advisor guidance for high-stakes decisions.
For another exam scale with official percentiles, use the MCAT score calculator. You can also plan coursework with the study score calculator, weighted grade calculator, or AP Biology score calculator.
Official score context
Step 1 is reported Pass/Fail
NBME self-assessment reports use EPC and an estimated probability of passing to help gauge readiness.
Step 2 CK passing score is 218
The standard applies to exams administered on or after July 1, 2025. Official reports remain primary.
Official sources
- NBMEComprehensive Basic Science Self-AssessmentOfficial CBSSA information for Step 1, including EPC reporting and estimated probability of passing.
- NBMEComprehensive Clinical Science Self-AssessmentOfficial CCSSA information for Step 2 CK, score reports, and readiness guidance.
- USMLEExamination Results and ScoringCurrent Step 1 reporting and the Step 2 CK minimum passing score of 218.
- USMLEScores and TranscriptsOfficial scoring context, including why the percent correct needed to pass can vary by test form.
Reviewed 1 August 2026
COMMON QUESTIONS
NBME score calculator questions
Direct answers about conversion, EPC, score prediction, offline calculation, and interpreting readiness.
How do I calculate an NBME score?
Choose Step 1 or Step 2 CK, select the matching NBME form, and enter either wrong answers or percent correct. The calculator returns a planning range. Your official NBME self-assessment report remains the source of record.
How accurate is an NBME score predictor?
It is useful for a rough study-planning range, not an exact official score. NBME statistically adjusts scores for form difficulty and does not publish one universal raw-to-score formula, so third-party results can differ from your report.
Why is my NBME EPC score lower than my raw percent correct?
Equated percent correct is statistically adjusted to account for small differences in difficulty among forms. NBME explains that EPC can therefore be slightly lower or higher than the literal percentage of questions you answered correctly.
How do I calculate an NBME score offline?
Count wrong answers out of 200 or calculate percent correct as correct answers divided by 200, then multiply by 100. You can enter either value here; the calculation runs locally in your browser, but the result is still only an estimate.
How are NBME exams scored?
NBME uses statistical equating so performance can be compared across forms with slightly different difficulty. Current Step 1 self-assessment reports emphasize EPC and probability of passing; Step 2 CK reports provide readiness information tied to the scored exam.
Do NBME scores correlate with Step scores?
They are designed to help gauge readiness, but one practice result cannot guarantee a future Step outcome. Testing conditions, time between assessments, learning, and normal score variation all matter.
What are NBME self-assessments scored out of?
The comprehensive Step 1 and Step 2 CK self-assessments contain 200 questions in four blocks of 50. Their official reports use equated results rather than treating a simple raw total as the final score.
Should one NBME result decide my exam date?
No. Use the official report, its score range or passing probability, your trend across multiple recent assessments, and guidance from your medical school or advisor before making a high-stakes scheduling decision.