Does UWSA1 overpredict USMLE Step 1 scores?

Yes. UWSA1 is known to overpredict Step 1 scores by approximately 10-15 points for most students. UWSA2 is significantly more accurate, typically predicting within ±5 points. This is why most study guides recommend using UWSA2 as your final readiness check.

What NBME score do I need to pass USMLE Step 1?

The Step 1 passing score is 196. To feel confident about passing, you should aim for 210-215 or higher on NBME practice exams, which corresponds to roughly 60-65% correct. Scores of 220+ on NBMEs indicate a greater than 90% probability of passing.

What is the passing score for USMLE Step 2 CK?

As of July 2025, the Step 2 CK passing score increased to 218 (previously 214). On NBME practice exams, aim for 230+ to have a comfortable margin. For competitive residency applications, most programs look for scores of 240-250+.

Should I average my NBME scores to predict my real score?

Averaging multiple NBME scores taken over your dedicated study period gives a better prediction than any single exam. However, weight your more recent exams more heavily, as they reflect your current knowledge level. Our multi-exam predictor uses weighted averaging to give you the most accurate estimate.

Free USMLE Score Calculator — NBME, UWSA & Step 1/Step 2 CK Predictor

Q: How accurate are NBME practice exams at predicting USMLE scores?

NBME practice exams are the most reliable predictors of USMLE performance when taken within 1-4 weeks of your exam. They typically predict your actual score within ±5-8 points for about 70-75% of students. Taking multiple NBMEs and averaging the predictions gives even better accuracy.

How the Calculator Works

This calculator uses form-specific linear regression formulas derived from thousands of student-reported NBME scores and their corresponding actual USMLE results. Each NBME form has a unique difficulty level, so each form gets its own conversion equation.

The basic formula for every NBME is: Predicted Score = Intercept – (Slope × Number of Wrong Answers). For example, NBME 25 uses 277.04 – (1.113 × wrong), meaning each wrong answer costs you roughly 1.1 points off a starting ceiling of 277.

For UWSA exams, the calculator applies a known adjustment factor because UWorld's self-assessments tend to overpredict. UWSA1 typically overpredicts by 10–15 points, while UWSA2 is more accurate with only a ~5-point overestimation for most students.

Important

No calculator can perfectly predict your real score. These are estimates based on population-level data. Your actual score depends on exam-day factors, content sampling, and how recently you took the practice exam. Use these predictions as one data point in your decision-making, not as a guarantee.

Step 1: NBME Score Conversion Formulas

Step 1 is now pass/fail (passing score: 196), but knowing your predicted three-digit score still matters because it strongly predicts your Step 2 CK performance — which is the scored exam residency programs care about.

Here are the form-specific conversion formulas used in this calculator. All are based on 200-question CBSSA exams:

NBME 25 (CBSSA 25): 277.04 – 1.113 × wrong. Moderate difficulty, strong pathology and pharmacology emphasis.
NBME 26 (CBSSA 26): 275.92 – 1.095 × wrong. Similar difficulty to 25, good baseline form.
NBME 27 (CBSSA 27): 279.82 – 1.138 × wrong. Slightly higher ceiling, harder questions.
NBME 28 (CBSSA 28): 277.18 – 1.105 × wrong. Moderate difficulty, balanced content.
NBME 29 (CBSSA 29): 278.40 – 1.090 × wrong. Good late-dedicated form.
NBME 30 (CBSSA 30): 280.50 – 1.150 × wrong. Considered the hardest form, highest points per question.
NBME 31 (CBSSA 31): 279.00 – 1.120 × wrong. Newest form with updated content.

Pro Tip

Take your NBMEs under real test conditions: timed, no breaks mid-block, no looking things up. Casual testing inflates your score and gives you a false sense of readiness.

Step 2 CK: NBME Score Conversion Formulas

Step 2 CK is the scored exam that residency programs weigh most heavily. The passing score increased to 218 as of July 2025 (previously 214). For competitive specialties, you want 250+.

CCSSA (Comprehensive Clinical Science Self-Assessment) form formulas:

NBME 9 (CCSSA 9): 298.45 – 1.09 × wrong. Good for early baseline.
NBME 10 (CCSSA 10): 300.18 – 1.10 × wrong. Slightly higher ceiling.
NBME 11 (CCSSA 11): 299.50 – 1.08 × wrong. One of the most predictive forms (r = 0.87).
NBME 12 (CCSSA 12): 300.18 – 1.09 × wrong. Strong late-stage assessment.
NBME 13 (CCSSA 13): 298.80 – 1.07 × wrong. Updated content, lower per-question penalty.
NBME 14 (CCSSA 14): 299.20 – 1.08 × wrong. Solid final-weeks form.
NBME 15 (CCSSA 15): 300.50 – 1.10 × wrong. Newest form, highest intercept.

UWSA1 vs UWSA2: Which Is More Accurate?

UWorld's self-assessments work differently — they give you a three-digit score directly, so you don't need to convert from percent correct. But those scores need adjustment:

UWSA1 consistently overpredicts by 10–15 points for Step 1 and 8–12 points for Step 2 CK. It's useful for gauging progress but not for final readiness decisions.
UWSA2 is the most accurate single predictor available. It typically matches actual scores within ±5 points for both Step 1 and Step 2 CK. Take it 1–2 weeks before your exam.
Free 120 is less about the score and more about getting comfortable with the actual USMLE interface. Scoring 70%+ on the Free 120 is a reasonable signal that you're in good shape.

Common Mistake

Don't anchor on a single practice exam score. If your NBME 29 was 230 but your NBME 30 was 210, the answer isn't "I'm probably around 230." Average your recent exams, weight the newer ones more, and look at the trend over time.

How to Use Your Predicted Score

For Step 1 (pass/fail)

If your predicted score is 215+ on at least two recent NBMEs, you're in strong shape to pass. If you're in the 196–210 range, consider pushing your test date by 2 weeks and focusing on your weakest systems. Below 196 on practice exams means you need more dedicated study time.

For Step 2 CK (scored)

Your target depends on your specialty. Generally: 230+ is safe to pass with a margin, 240–250 is competitive for most specialties, and 250+ puts you in a strong position for the most competitive programs. If your practice scores are flat, the issue is usually question review depth or burnout — not study volume. Talk to a tutor if you're stuck.

Frequently Asked Questions

How accurate are NBME practice exams at predicting USMLE scores?

NBME exams taken within 1–4 weeks of the real test typically predict your actual score within ±5–8 points for about 70–75% of students. Taking multiple NBMEs and averaging the results gives even better accuracy. The further out from your exam date, the less predictive any single practice test will be.

Does UWSA1 overpredict USMLE scores?

Yes. UWSA1 typically overpredicts Step 1 scores by 10–15 points and Step 2 CK scores by 8–12 points. UWSA2 is significantly more accurate, usually within ±5 points. This is why most study guides recommend UWSA2 as your final readiness check.

What NBME score do I need to pass Step 1?

The passing score is 196. We recommend aiming for 210–215+ on practice NBMEs to have a comfortable safety margin. Scores of 220+ correspond to a greater than 90% pass probability. Taking two NBMEs above 210 within your last 2 weeks of study is a good signal of readiness.

What is the passing score for Step 2 CK?

As of July 2025, the Step 2 CK passing score is 218 (increased from 214). For a comfortable margin, aim for 230+ on practice exams. For competitive specialties like dermatology or orthopedics, programs generally look for 250+.

Should I average my NBME scores?

Yes, with a caveat: weight your more recent exams more heavily. A simple approach is to take the average of your last 2–3 practice exams. If you see a clear upward trend, your real score is likely closer to your most recent exam than to the average.

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