The USMLE Free 120 is a set of 120 practice questions released directly by the NBME (National Board of Medical Examiners) on their official website. It is designed to represent the style, software interface, and difficulty level of the actual USMLE Step 1 exam. Because it is written by the actual test makers, it is considered one of the most valuable resources available to Step 1 candidates.

Save the Free 120 for the final 3–5 days before your exam. Take it under timed conditions to finalize your pacing strategy and content calibration. Do not let a low score panic you at this stage — focus on reviewing wrong answers rather than cramming new content. Use UWSA 2 roughly 7–10 days before your test date as your primary readiness estimator, then Free 120 in the final stretch.

Simulate test-day conditions. Take the Free 120 in blocks of 40 questions with a strict 60-minute limit per block. Put away your phone and notes. Review wrong answers thoroughly — spend 2–3 hours analyzing why you missed every incorrect question. Free 120 answer explanations are not provided by the NBME, so cross-reference with community sites or search platforms. Do not panic on obscure questions — the Free 120 always has a handful of experimental or highly unusual items. Focus your energy on checking your reasoning on standard, high-yield questions.

Historically, a percentage of 60% correct (roughly a 190 three-digit equivalent) has been the borderline threshold. For a safer pass margin, most tutors recommend aiming for 65–70%+ correct on the Free 120. Hitting 70%+ puts you well clear of the 196 passing threshold with a comfortable margin. Use UWSA 2 or NBME 31 alongside this for a fuller readiness picture.

The community-derived conversion formula is: Score = (Percentage Correct × 0.75) + 145. This is not official — since Step 1 moved to Pass/Fail, the NBME only reports your raw percentage correct out of 120. Tutors have long mapped these percentages onto the old three-digit scale using student-reported comparisons, and this calculator applies that same mapping.

No — the Free 120 does not give you a three-digit scaled score. Since Step 1 is Pass/Fail, you only receive your percentage correct and question-by-question correct/incorrect marks, with no official explanations. This is why this calculator exists — enter your percentage above for an instant predicted three-digit equivalent. At the Prometric testing center on exam day, a shortened orientation version of the Free 120 appears before your real exam — that orientation version is not graded. Only the full self-assessment at usmle.org generates meaningful percentage data.

Because the questions come directly from the writers of the USMLE, the vignettes, clinical phrasing, and distribution of laboratory values closely mirror what you’ll encounter on test day. Many students report seeing near-identical question concepts from the Free 120 on their real exams. It’s one of the most trusted final checkpoints available — but it’s still only 120 questions, so treat your result as one data point alongside your NBME and UWSA scores, not a guarantee.

The NBME periodically updates the Free 120 question set. The current version (often called the “New Free 120”) features longer clinical vignettes, a heavier emphasis on communication and ethics questions, and more multi-step reasoning items compared to older versions. Old Free 120 PDFs circulating on Reddit and Telegram are no longer representative of the current exam format — always use the current version at usmle.org for score prediction.

Each practice exam plays a specific role in your Step 1 preparation. NBME Forms 25–31: use throughout your dedicated period (every 1–2 weeks) to identify system-based weaknesses and track your trajectory — these questions are shorter and test raw recall. UWSA 2: take roughly 7–10 days before your test date — longer vignettes, an outstanding estimator of overall reasoning and content application. Free 120: save for the final 3–5 days — take it timed to finalize pacing and content calibration.

On the official USMLE website version, you can take breaks between blocks but not within a block. The Free 120 is divided into three blocks of 40 questions, each with a 60-minute limit. Take it with the timer enabled and simulate exam conditions — the real Step 1 is time-pressured, and untimed Free 120 performance does not reflect your actual exam-day ability.

Same-day wrong answer review is the highest-yield activity in your final days. (1) Identify the concept tested in each wrong answer — pathophysiology, pharmacology mechanism, or a specific lab value pattern. (2) Identify subject clustering — if several wrong answers cluster in Biochemistry or Pharmacology, that’s your priority for the remaining days. (3) Write a one-sentence rule for each wrong answer so the concept sticks. (4) Cross-check against your NBME and UWorld incorrects — overlap flags genuinely high-yield gaps. Save all 120 questions for one high-quality timed session; retake data isn’t meaningful once you’ve seen the questions.