From the 2026/1 diet, the MRCP(UK) Part 1 pass mark is 450, and the single most important fact about that number is what it is not: it is not 45%, it is not a fixed count of correct answers, and it is not directly comparable to the historical figure of 540 that older articles still quote. It is an equated scaled score, a statistically anchored point on a reporting scale, and understanding that properly changes how candidates should read their question-bank percentages, judge readiness and interpret results day. Checked against the Federation's published guidance, 29 August 2026.
What an equated scaled score actually is
Every MRCP Part 1 paper is built from different questions, and different questions have different difficulty; a raw mark of, say, 60% on a hard paper represents more ability than 60% on an easier one. Equating is the statistical process that corrects for this: performance on each diet is placed onto a common scale using anchor items and psychometric modelling, so that a given scaled score represents the same underlying ability whichever paper was sat. The pass mark is then expressed on that scale, currently 450, which means the standard is constant across diets while the raw percentage needed to reach it varies with each paper's difficulty. Candidates on a harder paper need fewer raw marks to reach 450; candidates on an easier paper need more; and the fairness of the examination lives precisely in that adjustment.
Why 450 is not 45%, and 540 was not 54%
The scaled score and the percentage axis are different instruments that happen to share digits, and the coincidence misleads every cohort. There is no fixed raw percentage that equals 450, because the conversion shifts with paper difficulty diet by diet; the college does not publish a stable percentage target because none exists. The same logic applies retrospectively to 540: it was a point on the previous reporting arrangement, not 54% of questions, and its replacement by 450 reflects a change in the scale and standard-setting presentation, not a dramatic lowering of the bar. Older iatroX and third-party articles quoting 540 should now be read as historical, and this page is the current canonical explanation.
What this means for question-bank percentages
The practical question every candidate asks: what bank percentage means I will pass? The honest answer is that no bank percentage converts into a scaled 450, for reasons that compound. Bank questions are not equated to the live examination; bank difficulty differs from paper difficulty, and differs again between banks; repeated exposure inflates bank scores through memory rather than ability; and adaptive banks, which deliberately serve questions at the edge of your ability, suppress percentages by design while improving learning. A bank score is a training signal, not a forecast, and the fuller treatment of why 70% in one bank is not 70% in another is at /blog/why-qbank-percentages-are-not-comparable. Better readiness markers than any single percentage: stable performance on genuinely unseen questions, full timed mocks under examination conditions, coverage across the blueprint rather than strength in favourite topics, and no weak domain left below a floor you have set deliberately.
How to use the change in your preparation
Three adjustments, none dramatic. First, stop chasing a magic percentage: train against the blueprint, use unseen-question performance as your signal, and treat any resource still promising "you need X% to pass" as dated. Second, read your results correctly on the day they arrive: your score and the 450 threshold are on the same equated scale, so the gap between them is meaningful in a way raw percentages never were, and a near-miss is informative about distance rather than bad luck. Third, ignore diet-difficulty folklore: equating exists precisely so that choosing a sitting by rumoured easiness confers no advantage, and the energy is better spent on coverage and timing.
Frequently asked questions
Did the exam get easier or harder with the change to 450?
Neither: the standard is maintained by equating, and the new figure is a change of scale and presentation; difficulty folklore around the transition has no basis in the mechanism.
Where does 540 still apply?
Nowhere current: it belongs to diets before 2026/1 and should appear only in expressly historical discussion; any preparation resource quoting it as the live pass mark has not updated.
What raw percentage should I aim for in practice?
Aim at coverage and unseen-question stability rather than a number; as a working habit, candidates who are comfortably passing full unseen timed mocks across the blueprint are preparing correctly, whatever the percentage on any particular bank says.
Does the 450 standard apply to Part 2 as well?
Each MRCP examination reports on its own equated arrangements; check the Federation's current guidance for the paper you are sitting rather than transferring figures between parts, since the principle travels but the numbers do not.