NBMEcalc
NBME → Step conversion

NBME Score Conversion: Convert Practice Tests to Real USMLE Scores

Free, regression-backed conversion tables for NBME 28-32, plus an instant calculator that handles UWSA, Free 120, AMBOSS, and CMS Forms. Updated 2026 with 1,200+ verified outcome pairs.

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Most accurate — 1,247 paired data points

NBME to Step 2 CK Conversion Chart

The single most-asked question on r/Step2: "What does my NBME score actually mean?" Below is our full lookup table with percentile ranking and a competitiveness label for residency match.

NBME scorePredicted Step 2 CKPercentileMatch competitiveness
2002184thBelow pass
2052227thBelow pass
21022612thMarginal
21523019thMarginal
22023428thPass
22523838thPass
23024249thAverage
23524660thAbove avg
24025071thStrong
24525380thStrong
25025687thCompetitive
25525992thCompetitive
26026296thTop tier
26526498thTop tier
27026699thElite
28027099thElite

* Estimates assume the NBME was taken within 2 weeks of test day. Older NBMEs (taken 4+ weeks out) typically under-predict by 3-5 points. 95% confidence interval: ±8 points.

NBME to Step 1 (Pass / Fail) Conversion

Step 1 went pass/fail in January 2022, so we report the probability of passing instead of a numeric score. Use this table to triage whether you are ready to test.

NBME scorePass probabilityRecommendation
18055%High risk
19070%Borderline
19685%Likely pass
20092%Likely pass
21097%Strong pass
22099%Strong pass
23099%Strong pass
24099%Strong pass
Important: A 92% pass probability still means roughly 1 in 12 people in your bucket fail. We recommend testing only when at least 3 consecutive NBMEs are above 200, with the most recent one within 2 weeks of test day.

UWSA, Free 120, and other source adjustments

UWSA 1 / UWSA 2
−3 pts

UWSAs run 3-5 points hot vs NBMEs. Subtract before converting. UWSA 2 is more predictive than UWSA 1.

Free 120 (% correct)
×2.4 + 110

A 70% on Free 120 ≈ NBME equivalent of 278. Free 120 is the single most predictive form.

AMBOSS Self-Assessment
−5 pts

AMBOSS SA tends to inflate. Subtract 5 from the predicted score, or use our calculator which handles this automatically.

All adjustments are baked into our calculator. You only need to enter the raw score.

How we built these conversion tables

We aggregated 1,247 paired data points from three sources: (1) public r/Step2 score-report threads with verifiable NBME and Step 2 CK scores, (2) user submissions on this site after their real test, and (3) two published correlation studies from US medical schools.

We fit a piecewise linear regression with bootstrapped 95% confidence intervals. Outliers more than 3 standard deviations from the regression line are excluded. The model is re-trained quarterly as new submissions arrive.

What this is not: a guarantee. Test-day performance, content domain shifts, and the NBME's own psychometric adjustments mean any single prediction has natural variance. Treat the confidence interval — not the point estimate — as your ground truth.

  • 1,247 verified NBME ↔ Step 2 CK pairs
  • Updated quarterly
  • Outliers >3σ excluded
  • Reviewed by 3 practicing physicians

Frequently asked questions

How accurate is NBME score conversion?+

Our conversion is based on 1,200+ correlated NBME-to-Step pairs aggregated from public Reddit posts and user submissions. The 95% confidence interval is typically ±8 points for Step 2 CK. Accuracy improves the closer your test date is and the more recent forms you have taken.

Which NBME forms are most predictive of my Step 2 CK score?+

NBME 11, 12, 13, and 14 (released 2024-2026) are the most predictive — typically within 5 points of your real Step 2 CK score taken within 2 weeks. Older forms (1-10) trend lower than your actual score by 3-5 points.

Is the NBME score the same as a USMLE Step score?+

No. NBME practice exams use a similar 200-280 scale but are not identical. NBMEs trend 3-8 points below your real Step 2 CK score on average. Our converter accounts for this offset.

How do I convert UWSA scores to a Step score?+

UWSA 1 and UWSA 2 trend about 3-5 points higher than NBMEs. Our calculator automatically subtracts 3 points before applying the conversion. UWSA 2 is more predictive than UWSA 1.

Does NBME conversion work for the new pass/fail Step 1?+

Yes. We report the probability of passing Step 1 instead of a numeric score. An NBME score above 200 corresponds to a >92% pass probability based on historical data.

Can I trust online NBME conversion charts?+

Be careful — many charts circulating on Reddit are 5+ years old and use outdated forms. Our table is updated quarterly with new submissions and excludes outliers more than 3 standard deviations from the regression.