NBME 13 Score CalculatorStep 2 CK Gold Standard — Late Dedicated Scheduling Checkpoint
200 questions · Week 6 of dedicated study. Enter wrong answers to get your predicted 3-digit Step 2 CK score instantly. NBME 13 is widely considered the most predictive NBME form for Step 2 CK — the benchmark most students rely on before making their scheduling decision.
NBME 13 Slightly Overpredicts — Subtract ~3 Points Before Scheduling
Community data suggests NBME 13 overpredicts actual Step 2 CK scores by approximately 3 points on average (range: 0–7 pts for most students). Subtract 3 pts from your predicted score before making your scheduling decision. If your adjusted score exceeds 221, you are likely ready. No peer-reviewed predictive accuracy study exists for Step 2 CK — this reflects community consensus from r/step2 and SDN.
Why NBME 13 Is the Most Trusted Step 2 CK Predictor
NBME 13 earns its gold standard reputation from two factors: question style and timing. Its questions use long HPI-format stems — the same narrative patient history format used on the real Step 2 CK exam. Each question requires multi-step clinical reasoning: identify the diagnosis, understand the pathophysiology, and select the next best management step. This mirrors what the real exam actually tests, making NBME 13 scores more transferable to actual performance than forms with shorter, more isolated question stems.
NBME 13 is taken in Week 6 of dedicated study, when preparation is approaching its peak. Research for Step 1 (Fan et al. 2024, Med Sci Educ, PMC11933626) found that practice test classification accuracy drops sharply when taken more than 2 weeks before the exam. While no equivalent published study exists for Step 2 CK, the same principle applies: NBME 13 is most predictive in this final window, not taken earlier.
NBME 13's predictive accuracy reflects community consensus from r/step2 and SDN — not a peer-reviewed published study. No Step 2 CK practice exam has published R² or formal bias data equivalent to Seal et al. 2020 (Cureus, PMC7198101) for Step 1.
NBME 13 Score Benchmarks — What Your Score Means for Residency
Subtract ~3 pts from your predicted score before comparing to specialty targets. Passing threshold: 218 (USMLE.org, effective July 1, 2025).
| Wrong Answers | Predicted Score | Specialty Signal |
|---|---|---|
| 15 | ~283 | Exceptional — competitive specialty territory |
| 25 | ~272 | Strong — well above competitive cutoff |
| 35 | ~261 | Good — above 240 competitive threshold |
| 50 | ~245 | Solid — within competitive specialty range |
| 60 | ~235 | Above safe zone (230+) — ready for most specialties |
| 70 | ~224 | Near safe zone — borderline for competitive programs |
| 75 | ~219 | Just above passing — do not schedule yet |
| 76+ | <218 | Below passing — do not schedule |
Formula: 298.80 − 1.07 × wrong answers. Specialty thresholds: 230+ safe zone, 240+ competitive (Surgery, Dermatology, Orthopaedics, Neurosurgery). Community consensus, not official NRMP data.
NBME 13 vs NBME 14 / 15 / UWSA 2 — Late Dedicated Comparison
| NBME 13 | NBME 14 | NBME 15 | UWSA 2 | |
|---|---|---|---|---|
| Slope (pts/wrong) | 1.07 | 1.08 | 1.10 | 1.08 |
| Questions | 200 | 200 | 200 | 160 |
| Difficulty | Hard | Hard | Hard | Hardest |
| Recommended timing | Week 6 | Final 2–3 weeks | Final 2–3 weeks | Final 7–10 days |
| Avg. overprediction | ~3 pts | Limited data | Very limited data | ~5 pts |
| Primary use | Scheduling check | Guideline check | 2026 content check | Final scheduling signal |
| Data source | Community | Community | Community | Community |
Community consensus data. No peer-reviewed predictive accuracy study exists for any Step 2 CK practice assessment. UWSA 2 remains the recommended final scheduling signal in the last 7–10 days before exam.
NBME 13 Score Conversion Table — Step 2 CK
| Wrong | Correct | % Correct | Predicted Score | Pass Prob |
|---|---|---|---|---|
| 0 | 200 | 100% | 299 | 99.9% |
| 5 | 195 | 97.5% | 293 | 99.9% |
| 10 | 190 | 95% | 288 | 99.9% |
| 15 | 185 | 92.5% | 283 | 99.9% |
| 20 | 180 | 90% | 277 | 99.9% |
| 25 | 175 | 87.5% | 272 | 99.9% |
| 30 | 170 | 85% | 267 | 99.9% |
| 35 | 165 | 82.5% | 261 | 99.9% |
| 40 | 160 | 80% | 256 | 99.9% |
| 45 | 155 | 77.5% | 251 | 99.7% |
| 50 | 150 | 75% | 245 | 99.2% |
| 55 | 145 | 72.5% | 240 | 98.1% |
| 60 | 140 | 70% | 235 | 95.5% |
| 65 | 135 | 67.5% | 229 | 87.9% |
| 70 | 130 | 65% | 224 | 74.6% |
| 75 | 125 | 62.5% | 219 | 54.5% |
| 80 | 120 | 60% | 213 | 28.9% |
| 85 | 115 | 57.5% | 208 | 14.2% |
| 90 | 110 | 55% | 203 | 6.3% |
| 95 | 105 | 52.5% | 197 | 2.2% |
| 100 | 100 | 50% | 192 | 0.9% |
| 105 | 95 | 47.5% | 186 | 0.3% |
| 110 | 90 | 45% | 181 | 0.1% |
| 115 | 85 | 42.5% | 176 | 0.1% |
| 120 | 80 | 40% | 170 | 0.1% |
| 125 | 75 | 37.5% | 165 | 0.1% |
| 130 | 70 | 35% | 160 | 0.1% |
| 135 | 65 | 32.5% | 154 | 0.1% |
| 140 | 60 | 30% | 149 | 0.1% |
| 145 | 55 | 27.5% | 144 | 0.1% |
| 150 | 50 | 25% | 140 | 0.1% |
| 155 | 45 | 22.5% | 140 | 0.1% |
| 160 | 40 | 20% | 140 | 0.1% |
| 165 | 35 | 17.5% | 140 | 0.1% |
| 170 | 30 | 15% | 140 | 0.1% |
| 175 | 25 | 12.5% | 140 | 0.1% |
| 180 | 20 | 10% | 140 | 0.1% |
| 185 | 15 | 7.5% | 140 | 0.1% |
| 190 | 10 | 5% | 140 | 0.1% |
| 195 | 5 | 2.5% | 140 | 0.1% |
| 200 | 0 | 0% | 140 | 0.1% |
About NBME 13
Gold standard for pure Step 2 CK score prediction.
Highest predictive accuracy among all Step 2 CK forms per community data. Best single predictor if taken 1–3 weeks before exam.
Other Step 2 CK Practice Exams
NBME 13 Step 2 CK Calculator — FAQ
This tool is for educational purposes only. Not affiliated with NBME® or USMLE®. Predictions carry an estimated error of ±5–10 points. No peer-reviewed study has published form-specific predictive accuracy data for Step 2 CK practice assessments. All bias figures and specialty score thresholds reflect community consensus from r/step2 and SDN forums. Passing threshold (218) per USMLE.org, effective July 1, 2025.