UWorld vs AMBOSS for Step 2 CK
Both question banks measured against the real exam scores of the students who used them, across 2,542 score reports from r/Step2.
Summary of the results
Among 2,542 score reports from r/Step2, 89% mention UWorld and 9% mention the AMBOSS Qbank; 2,178 and 57 of them pair a percent correct with a real exam score. The AMBOSS group is smaller, so there is more uncertainty around its estimates. The main results were:
- In the small paired sample (n = 40), AMBOSS percentages were a median 4.5 points higher, but usage order and session settings prevent a question-difficulty conclusion.
- A given percent correct maps to nearly the same Step 2 score on either bank. A 70% average maps to roughly 258 in both datasets.
- Total question count had a small positive relationship with the final score across 431 reports (r = 0.14); second-pass comparisons were positive in all three accuracy bands.
- The score difference between students who used a second qbank and those who did not was a few points at mid-range UWorld accuracy and smaller in the 75%+ band (+1.5 points).
The same percentage maps to nearly the same score
The average Step 2 score was estimated separately for each bank. From 60% to 80%, the estimates remain within 2 points of each other.
| Qbank average | Step 2 if it is UWorld | Step 2 if it is AMBOSS |
|---|---|---|
| 60% | 250 | 249 |
| 65% | 254 | 253 |
| 70% | 258 | 257 |
| 75% | 263 | 262 |
| 80% | 267 | 266 |
These are estimated group averages. They reflect how each bank was used, including timing and session settings. The UWorld column is based on 2,178 reports and the AMBOSS column on 57.
The main predictor combines your qbank average with practice exams and assessment dates.
Every report on one chart
Each dot is one real score report; teal dots are AMBOSS Qbank averages and can be hovered or tapped for that person's full test list. The dashed line shows the UWorld trend and the solid line shows the AMBOSS trend. They run nearly on top of each other.
Real scores by qbank average
UWorld (n = 2,178)
| UWorld average | Average Step 2 | Median | Reports |
|---|---|---|---|
| 50–54% | 242 | 244 | 63 |
| 55–59% | 248 | 249 | 215 |
| 60–64% | 252 | 253 | 369 |
| 65–69% | 256 | 257 | 527 |
| 70–74% | 260 | 261 | 439 |
| 75–79% | 264 | 265 | 323 |
| 80%+ | 269 | 270 | 230 |
AMBOSS Qbank (n = 57)
| AMBOSS average | Average Step 2 | Median | Reports |
|---|---|---|---|
| 60–69% | 252 | 253 | 20 |
| 70–79% | 260 | 261 | 24 |
| 80–89% | 272 | 273 | 8 |
AMBOSS rows are small samples, hence the wider bands; rows under 5 reports are hidden.
What the same-student reports show
Among the 40 students who reported a percent on both banks, the AMBOSS percentage was a median 4.5 points higher and 65% reported a higher AMBOSS percentage.
Usage order limits the comparison. 10 of the 40 explicitly described doing AMBOSS after UWorld, switching banks midway or saving AMBOSS for dedicated; 0 described the reverse. That stated-order group had a median difference of +9.0 points on AMBOSS relative to the earlier UWorld percentage. Score reports did not consistently include session settings, so these data cannot measure the effect of including or excluding 5-hammer questions.
Because bank order and question settings differed or were missing, the percentage gap cannot establish question-level difficulty. The separate percent-to-score mappings above answer a different question: the same reported percentage pointed to a similar final Step 2 score on either bank.
Does doing both banks help?
Students who used both banks averaged 261 against 257 for UWorld-only, a 3.7-point gap. Much of that difference reflects who completes two banks. Comparing students with the same UWorld accuracy reduces the gap:
| UWorld average | UWorld only | Both banks | Difference |
|---|---|---|---|
| 55–64% | 250 | 255 | +4.5 |
| 65–74% | 258 | 262 | +4.4 |
| 75–89% | 265 | 267 | +1.5 |
The same pattern appears when students with similar NBME scores are compared: those who used both banks finished about 2.1 points higher. The observed gap linked with a second qbank was a few points at middle UWorld accuracy and smaller, but still positive, in the 75%+ band (+1.5 points). Students chose their own study plans, so this does not prove that adding a second qbank caused the score gap. Finish and review one bank first; add the second only if your accuracy has plateaued and the calendar allows it.
Question volume and final scores
Combine each report's completion percentages with the banks' sizes (about 4,300 UWorld and 3,400 AMBOSS questions) and you get total questions completed for 431 reports. The correlation with the final score was r = 0.14, a small positive relationship in these reports.
| Questions completed | Average Step 2 | Median | Reports |
|---|---|---|---|
| Under 1,500 | 254 | 253 | 29 |
| 1,500–2,500 | 253 | 254 | 70 |
| 2,500–3,500 | 254 | 254 | 157 |
| 3,500–4,300 | 257 | 257 | 90 |
| 4,300+ | 258 | 259 | 85 |
Reports under 1,500 questions averaged 254, compared with 258 among reports at 4,300 or more. Within the 65–74% UWorld band, completion-group averages spanned about 5.1 points. By comparison, percent correct had the stronger relationship with the final score (r = 0.58). Accuracy tracked the final score more closely than total volume did.
Students who begin with lower practice scores may choose to complete more questions, which can complicate the simple averages. In these reports, higher early practice scores were instead weakly associated with more questions (r = +0.16, n = 164). Improvement was similar at the volume extremes: from the earliest test to the real exam, students under 1,500 questions gained +29 points on average while students past 4,300 gained +27. After accounting for earlier practice scores, the difference was about +0.7 points per 1,000 questions. Students were not assigned to different question totals, and completion is self-reported. Cover the content, review missed concepts, and use practice exams to measure progress.
Second-pass results depended on first-pass accuracy. Among students with the same first-pass accuracy, those who did a second pass of UWorld outscored single-pass students by +5.4 points when the first pass landed at 55–64%, by +4.2 at 65–74%, and by +2.5 at 75% and up (312 second-pass reporters). The comparison is between students who scored the same on their first pass, which reduces the effect of stronger students being more likely to repeat. The observed differences were positive in every band and do not support a sharp 75% cutoff. Students chose their own study plans, so neither comparison proves that doing more questions or a second pass caused the higher scores.
Self-assessment comparison
Both companies also sell full-length self-assessments, which beat any qbank percentage as predictors. The table reports each assessment's typical error when used by itself after accounting for when it was taken, plus its median difference from the real exam.
| Self-assessment | Reports | Typical error | Real exam vs test, median |
|---|---|---|---|
| UWSA 1 | 1,729 | ±6.5 | +15 |
| UWSA 2 | 1,918 | ±6.0 | +5 |
| UWSA 3 | 385 | ±6.3 | +17 |
| AMBOSS Self-Assessment | 573 | ±7.0 | +16 |
UWSA 2 had the smallest typical error in this group, while UWSA 1, UWSA 3, and the AMBOSS self-assessment were within about a point of it. These figures describe the students who reported each assessment and are not a randomized head-to-head comparison. Conversion guides: UWSA 1, UWSA 2, UWSA 3 and AMBOSS SA.
Which should you use?
UWorld has the larger evidence base in these reports: 2,178 students listed a UWorld percentage, which makes its conversion more precise. This dataset cannot compare how well the two banks teach. AMBOSS may be preferable if you value its integrated library or have already completed UWorld during clerkships. Whichever bank you choose, review it carefully and use practice exams to track readiness. The free predictor takes your qbank average, whichever bank it came from, and weighs it alongside everything else.
Common questions
Is the AMBOSS Qbank harder than UWorld?
These reports cannot establish question-level difficulty. Among 40 students reporting both banks, the AMBOSS percentage was a median 4.5 points higher and 65% reported a higher AMBOSS percentage. 10 explicitly used AMBOSS after UWorld, and session settings were not reported consistently. A given reported percentage mapped to about the same final score on either bank.
What does 70% on the AMBOSS Qbank mean for Step 2?
The estimated average was about 257 on Step 2, compared with 258 for a 70% UWorld average. The AMBOSS estimate is based on 57 reports, so there is more uncertainty around it.
Do I need to do both UWorld and AMBOSS?
Students who used both banks scored about 4 points higher on average. Much of that gap reflects differences between students who used one bank and those who completed two. At the same UWorld percentage, the gap was about 4 points in the mid band and +1.5 in the 75%+ band. Students chose their own study plans, so this does not prove that adding a second bank caused the difference.
How many practice questions are enough for Step 2?
Across 431 reports with completion data, total questions completed had a small positive relationship with the final score (r = 0.14). Within the 65–74% UWorld band, completion-group averages spanned about 5.1 points. Improvement from the earliest practice test was similar at the volume extremes. After accounting for earlier practice scores in 164 reports, the difference was about +0.7 points per 1,000 questions. This does not prove that doing more questions caused the higher score because students chose their own study plans.
Which predicts Step 2 better, UWorld or AMBOSS?
Their correlations with the final score were nearly identical: r = 0.58 for UWorld and r = 0.61 for AMBOSS. The UWorld estimate is based on 2,178 reports, compared with 57 for AMBOSS, so there is less uncertainty around it. The main predictor gives more weight to practice exams because they predicted better than either qbank percentage.
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Charts & guides
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