The MCAT has a real syllabus. The Association of American Medical Colleges (AAMC) organises the three science sections around ten "foundational concepts" and publishes, for each section, what percentage of questions draws on each university discipline. That makes it one of the few admissions tests where you can plan revision against official weightings, and this page sets them out from the AAMC's own pages, alongside the Myndaq MCAT course.
The four sections
- Chemical and Physical Foundations of Biological Systems — 59 questions, 95 minutes: 10 passage-based sets of 4–6 questions and 15 independent questions.
- Critical Analysis and Reasoning Skills (CARS) — 53 questions, 90 minutes: 9 passage-based sets of 5–7 questions.
- Biological and Biochemical Foundations of Living Systems — 59 questions, 95 minutes: 10 passage-based sets and 15 independent questions.
- Psychological, Social, and Biological Foundations of Behavior — 59 questions, 95 minutes: 10 passage-based sets and 15 independent questions.
That is 230 questions and 6 hours 15 minutes of testing; with breaks and check-in you are at the test centre for about 7 hours 30 minutes. Each section includes some unscored field-test questions you cannot identify.
The science content, in the AAMC's words, "draws from disciplines in year-long courses in general chemistry, organic chemistry, introductory physics, and introductory biology and from introductory courses in biochemistry, psychology, and sociology".
Chemical and Physical Foundations
Disciplines, by share of questions:
- General chemistry — 30%
- First-semester biochemistry — 25%
- Introductory physics — 25%
- Organic chemistry — 15%
- Introductory biology — 5%
Foundational concepts: Concept 4 — 40%, Concept 5 — 60%.
Physics is a quarter of this section. Because the section's title is the chemical and physical foundations of biological systems, expect physics set in biological contexts rather than as abstract mechanics — practise it that way.
Biological and Biochemical Foundations
- Introductory biology — 65%
- First-semester biochemistry — 25%
- General chemistry — 5%
- Organic chemistry — 5%
Foundational concepts: Concept 1 — 55%, Concept 2 — 20%, Concept 3 — 25%.
Biochemistry appears in both science sections at 25% each, which makes it, measured across the test, one of the most heavily examined disciplines. Candidates who treat it as a single short course under-prepare.
Psychological, Social, and Biological Foundations
- Introductory psychology — 65%
- Introductory sociology — 30%
- Introductory biology — 5%
Foundational concepts: Concept 6 — 25%, Concept 7 — 35%, Concept 8 — 20%, Concept 9 — 15%, Concept 10 — 5%.
This is the section candidates from a pure science background find least familiar and most learnable: it is largely vocabulary and models from two introductory courses, applied to passages.
Critical Analysis and Reasoning Skills
CARS needs no outside knowledge. Its passages come from the humanities and social sciences, and the questions test comprehension, reasoning within the text, and reasoning beyond it. Nine passage sets in 90 minutes is 10 minutes per passage and its questions — the pace, not the content, is what has to be trained.
Turning weightings into a study plan
A simple way to use the percentages: estimate your current strength in each discipline, multiply the gap by the weighting, and start where the product is largest. A weak candidate in biochemistry faces a quarter of two sections; a weak candidate in organic chemistry faces 15% of one section and 5% of another. The weightings will not tell you which topics within a discipline appear most, so after the first pass, let your own practice errors decide.
How the MCAT is scored
- Each section: 118 to 132.
- Total: 472 to 528.
- Wrong answers are scored the same as unanswered questions — no penalty for guessing.
- Scores are scaled and equated across administrations, not curved, and released 30 to 35 days after test day.
There is no pass mark; medical schools publish the scores of their admitted classes.
Reading the weightings
Add the three science sections together and two disciplines dominate: biology (5% + 65% + 5%) and biochemistry (25% + 25%). General chemistry and physics are concentrated in the first section; psychology and sociology in the fourth. The weightings describe the typical balance of a test form, not a guarantee for any one sitting.
For a study plan, see the MCAT preparation guide. For fees and rescheduling rules, see MCAT fees and registration. For worked questions in all four sections, see MCAT practice questions.
Quick answers
What is on the MCAT?
Four sections: Chemical and Physical Foundations, CARS, Biological and Biochemical Foundations, and Psychological, Social and Biological Foundations — 230 questions in 6 hours 15 minutes.
How much of the MCAT is biochemistry?
25% of the Chemical and Physical Foundations section and 25% of the Biological and Biochemical Foundations section.
How much physics is on the MCAT?
Introductory physics is 25% of the Chemical and Physical Foundations section, and does not appear in the other sections' discipline lists.
Is there negative marking on the MCAT?
No. The AAMC scores wrong answers the same as unanswered questions.
Does CARS need outside knowledge?
No. Everything needed is in the passage.
