Every spring, students who have finished precalculus face the same form: AB or BC? Most of the advice they get is about prestige. The actual difference is specific, and it decides the right choice better than reputation does. This page sets out what each course covers, how the exams work, what colleges do with the scores, and who should take which.
The short answer
AB is Calculus 1. BC is Calculus 1 and most of Calculus 2, in the same year. Everything in AB is in BC, tested at the same level. BC adds about a semester of extra material, most importantly infinite series. So BC is harder because it is faster and because of series, not because it treats the shared topics more deeply.
Topic by topic
| Topic | AB | BC |
|---|---|---|
| Limits and continuity | Yes | Yes |
| Derivatives: definition, rules, chain rule, implicit | Yes | Yes |
| Applications of derivatives: related rates, optimisation, curve analysis | Yes | Yes |
| Integrals and the fundamental theorem | Yes | Yes |
| Integration techniques | Substitution | Substitution, integration by parts, partial fractions |
| Improper integrals | No | Yes |
| Differential equations | Separable; slope fields | Separable; slope fields; Euler's method; the logistic model |
| Applications of integrals: area, volume, average value | Yes | Yes, plus arc length |
| Parametric equations, polar curves, vector-valued functions | No | Yes |
| Infinite sequences and series: convergence tests, Taylor and Maclaurin series, error bounds | No | Yes |
The series unit is the one that separates the courses. It is a new kind of mathematics, it comes at the end of the year when there is little time, and it carries a large share of the BC exam.
Pace
An AB class spends the year on ten units and has time to practise each. A BC class covers the same ten in about two thirds of the year and then adds the BC units. Students describe BC less as "harder calculus" than as "no slack": a bad fortnight in BC costs a unit.
Some schools solve this with two years: AB in one year, then BC the next, which repeats the AB material and adds the BC units at an easy pace. If your school does that, the question answers itself.
The exams
Both exams have the same shape and length: about three and a quarter hours, two sections of equal weight. The multiple-choice section has 45 questions, part without a calculator and part with. The free-response section has six questions, again split by calculator use. The difference is in what the questions can draw on: the BC exam includes series, parametric and polar questions, and the extra integration techniques.
The AB subscore. Everyone who sits the BC exam gets two scores: the BC score, and an AB subscore computed from the questions on AB material. A student who scores 3 on BC may have an AB subscore of 4 or 5, and many colleges will use the subscore for Calculus 1 credit.
Pass rates, and why BC's look better
BC pass rates are consistently among the highest of any AP exam, around four in five students scoring 3 or above, against something over three in five for AB. This does not mean BC is easier. BC students are a self-selected group: the ones who were confident enough in precalculus to take the faster course. Read the two figures as a description of who takes each exam, not of how hard they are.
What colleges do with the scores
| Score | Typical credit |
|---|---|
| AB 4 or 5 | One semester of calculus (Calculus 1) |
| BC 4 or 5 | Two semesters (Calculus 1 and 2) |
| BC 3 with AB subscore 4 or 5 | Often Calculus 1, on the subscore |
| Any 3 | Depends entirely on the college; many give nothing for a 3 |
Policies vary widely, and selective colleges often require a 5 or give placement rather than credit. Check the specific college's AP credit page before deciding anything on the strength of credit.
For admissions rather than credit, colleges look at whether you took the most demanding course available to you. For engineering, physics, mathematics and computer science applicants, BC is expected where the school offers it. For most other majors, a strong AB score is fine.
Who should take which
| Your situation | Take |
|---|---|
| A in precalculus, found it comfortable, aiming for engineering, physics, maths or computer science | BC |
| A or B in precalculus, undecided major | BC if the school's BC is a single year and you work steadily; otherwise AB |
| B or C in precalculus, or precalculus was a struggle | AB, done well |
| School teaches AB then BC over two years | Follow the sequence |
| Only AB offered | AB, then Calculus 2 at college |
| Senior taking calculus for the first time, heavy course load | AB |
A 5 in AB is a better outcome than a 3 in BC, for credit, for the transcript and for what you actually know. Whether calculus itself suits you, course by course, is in is calculus hard, and the alternative for students not heading into STEM is weighed in calculus vs statistics.
If you take BC
Three things make the difference:
- Make the AB material automatic by the winter break. The BC units arrive in the spring and need all the time they can get.
- Start series early, on your own if you have to. Convergence tests and Taylor series need weeks of practice, and the class will give you days.
- Do released free-response questions from both exams. BC free-response questions on AB topics are the same questions; practising both doubles your material.
Where to get help
A 1-on-1 online class for AP Calculus BC and AP Calculus AB with a tutor who holds a master's in mathematics: a unit ahead of the class, the series unit started in the winter, and released free-response questions marked to the College Board's own scoring guidelines. The free 30-minute first class is a real lesson on the unit you are on.
Questions parents ask
1What is the difference between AP Calculus AB and BC?
2Is AP Calculus BC harder than AB?
3Does the BC exam give an AB score?
4Which gives more college credit?
5Should I skip AB and take BC?
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Shobha
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Teaching maths, science and English to children online since 2018. 500+ students, 20+ tutors, families in nine countries.