AP Calculus BC Study Guide: The Two Units AB Skips

An AP Calculus BC study guide has to begin where AB stops. BC holds all eight AB units plus two more, and the College Board weights Unit 9 at 10 to 15 percent of the multiple-choice section and Unit 10 at 15 to 20 percent. Let that weighting decide how you spend your months.

The sentence you will hear most often about this course is that BC is AB with a few extras on top. That undersells the gap twice over. Two whole units are taught only in BC, and there are additional BC-only topics sitting inside three of the units the two courses appear to share. The study method does carry across: our AP Calculus AB guide writes out the method in full, and everything in it applies here. What does not carry across is the material, so this guide is about the difference and what it costs you in study time.

What does AP Calculus BC cover that AB does not?

The College Board answers this in one place, a post comparing the two courses dated January 14, 2026. It states that AP Calculus AB focuses on topics taught in the college-equivalent first-semester calculus class, while AP Calculus BC focuses on topics covered in both the first-semester and second-semester classes. It also states that all topics in the eight units of AP Calculus AB are also included in AP Calculus BC, and that BC contains two additional units, Units 9 and 10, plus some extra topics in Units 6 to 8.

That page names the BC-only topics, and the list is longer than most students expect: additional techniques of integration in Unit 6, the Euler method and logistic models with differential equations in Unit 7, arc length and distance traveled along a smooth curve in Unit 8, parametric equations, polar coordinates, and vector-valued functions in Unit 9, and infinite sequences and series in Unit 10. Three of those five entries live inside units you share with AB. A BC student who works from an AB review book and assumes Units 6, 7 and 8 are already covered will finish it with named topics still missing.

Infinite series is the heaviest unit AB gives you no head start on

Unit 10, Infinite Sequences and Series, is listed at 15 to 20 percent of the multiple-choice section. That is the top band on the AP Central weighting table, and exactly one other unit shares it: Unit 6, Integration and Accumulation of Change. The two are not the same problem for you. Unit 6 is one of the eight units AB already teaches, so an AB textbook, an AB class, and an AB tutor all reach it. Unit 10 is taught only in BC, which means the heaviest band on that table holds a unit nothing outside your BC course prepares you for.

Series is also different in kind from most of the course. Elsewhere in BC you are handed a function and asked to run a procedure on it, and the procedure is decided by what you can see. A series question usually asks you to make a classification decision first, choosing which convergence test applies to the expression in front of you, and only then to compute. The computation is the part your other units trained. The choice is the part they did not.

The good news is that the choice is a closed one. The AP Calculus AB and BC Course and Exam Description, the PDF published from the course page, carries an exclusion statement in Unit 10 that names the tests you are responsible for: the nth term test for divergence, and the integral test, comparison test, limit comparison test, alternating series test, and ratio test for convergence. It then says other methods are not assessed on the exam, and that teachers may include additional methods if time permits. Six named tests is a list you can drill as a set, and knowing the list is closed turns an open-ended decision into a six-way one. The same document tells teachers that students need practice deciding which application fits a given scenario before applying the procedure, and it puts weight on establishing the conditions for using a particular test, so the skill comes from the course itself, and this guide only repeats it.

Two layers of that unit are pure memory work, and they repay being handled as memory work. The first is the set of standard Maclaurin series, which are worth knowing cold. The second is the condition attached to each convergence test, since a test named correctly and applied outside its condition earns nothing. Our guide on how to memorize formulas covers how to drill that kind of material so it survives to exam day.

The classification skill needs its own drill, separate from working full problems. Build a list of series expressions, cover the solutions, and practice naming the test and its condition with no computation at all. Ten of those take a few minutes and they train the exact decision that the rest of your practice keeps skipping past. This is the targeted, narrow repetition that deliberate practice describes, aimed at the one sub-skill that decides whether the rest of a question is even reachable.

How much of the BC exam do Units 9 and 10 account for?

Adding the two published ranges on the AP Central course page for AP Calculus BC gives 25 to 35 percent of the multiple-choice section. That is arithmetic on the two ranges the College Board prints, and not a figure it publishes itself. There is no point estimate available either, because every entry on that table is a range. Between a quarter and a third of the multiple-choice section sits on material AB never touches, which is the number that should be shaping your calendar.

Two caveats keep the number honest. The table is headed Exam Weighting (Multiple-Choice Section), so it describes one half of the exam, the half worth 50 percent of the score, and says nothing at all about how the six free-response questions distribute across the units. And AP Central presents the same ten units as one possible sequence for the course, with the note that teachers have flexibility to organize the content as they like, so the order you met the material in class is a local decision.

The BC page publishes a second table that is worth reading beside the unit weights. It weights the Mathematical Practices, and the two halves of the exam pull in different directions. Determining expressions and values using mathematical procedures and rules is 50 to 70 percent of the multiple-choice section and 35 to 60 percent of the free-response section. Justifying reasoning and solutions runs the other way, at 10 to 20 percent of the multiple-choice section and 35 to 60 percent of the free-response section. Using correct notation, language, and mathematical conventions is only assessed in the free-response section, where it is 10 to 25 percent. Fluent computation carries the first half of the paper. Written justification carries the second.

The AP Calculus BC exam format, and the date stamped on it

The AP Central exam page for AP Calculus BC currently publishes this shape, and the AP Students page gives the total duration as 3 hours 10 minutes.

• Section I is multiple choice. 42 questions in 1 hour 40 minutes, worth 50 percent of the exam score. Part A is 29 questions in 62 minutes with a calculator not permitted, worth 35 percent of the score. Part B is 13 questions in 38 minutes with a graphing calculator required, worth 15 percent.
• Section II is free response. 6 questions in 1 hour 30 minutes, worth the other 50 percent. Part A is 2 questions in 30 minutes with a graphing calculator required, worth 16.7 percent of the score. Part B is 4 questions in 60 minutes with a calculator not permitted, worth 33.3 percent. At least two questions incorporate a real-world context or scenario.
• It is a hybrid digital exam. You answer the multiple-choice questions and view the free-response questions in the Bluebook testing app, then handwrite your free-response answers in paper exam booklets that are returned for scoring. A sample free-response booklet is published for this exam, and test previews are available in Bluebook.
• The no-calculator work is the larger share. The two parts that ban a calculator carry 35 percent and 33.3 percent, which add to 68.3 percent of the score. That addition is arithmetic on the published shares, and it is the single most useful thing on this list for deciding how to practice.

Now the part a study guide has to date. Both AP Central pages for this course carry a block headed Clarifications and Exam Updates for 2026-27. It says the AP Calculus AB and BC Course and Exam Description has been updated with minor clarifications for the 2026-27 school year, that course content has not changed, and that the number of multiple-choice questions and the timing on the AP Calculus AB and BC exams have also been updated, with those updates effective starting with the May 2027 exams. The exam page lists the exam date as Monday, May 10, 2027, Session 1.

Read those two lines together, because apart they invite the wrong conclusion. The clarifications document linked from that block spells the change out: in Part A the number of questions was changed from 30 to 29 and the timing from 60 minutes to 62 minutes, and in Part B from 15 questions to 13 and from 45 minutes to 38. It is headed as being implemented for Fall 2026. So the old paper was 45 multiple-choice questions in 1 hour 45 minutes, and the 42 in 1 hour 40 printed on the exam page is the new shape, already published. The free response half is untouched at 6 questions in 1 hour 30.

Which makes this one of the few places a study guide can save you from an out-of-date source. Anything still telling you to pace against 45 questions, whether that is a prep book printed before the change or an answer on a forum, is describing the paper that came before yours. Pace against 42. Two minutes went onto Part A while seven came off Part B, so the calculator section is the one that tightened, and that is where timed practice earns the most. The reassuring half of the notice holds too: course content has not changed, so the unit list and the weightings in this guide are the ones to study from either way.

How should you study for AP Calculus BC?

The general method is the same one that wins an AB exam, and it is written out in the AB guide and in our subject guide on how to study calculus. What follows is only the part that changes because the course is BC.

• Start Unit 10 early, whatever order your class taught it in. Series sits tenth and last in the sequence AP Central publishes, which lands the heaviest-weighted unit with no AB foundation at the end of the year, where revision time is thinnest. AP Central calls that ordering one possible sequence, so nothing obliges your revision to copy it.
• Parametric is the half of Unit 9 to rebuild first. The two halves of that unit reach you in very different condition. Polar comes out of AP Precalculus Unit 3, Trigonometric and Polar Functions, which is examined and carries 30 to 35 percent of the multiple-choice section on that exam, so most students arrive having drilled it. Parametric sits in Unit 4, Functions Involving Parameters, Vectors, and Matrices, which the College Board states is not assessed on the AP Precalculus exam at all. Our AP Precalculus guide is right to tell readers not to let that unit eat their revision time, and the consequence lands here: parametric work is the least-drilled material a BC student owns on the day Unit 9 opens, and it is the half to rebuild first.
• Weight your practice toward the no-calculator parts. They carry 68.3 percent of the score between them, which means clean by-hand algebra and by-hand integration are worth more of your practice hours than calculator technique is.
• Work the released free-response questions and score them. AP Central provides access to the three most recent years of released exam materials for this course, with free-response questions, scoring guidelines, chief reader reports, scoring statistics, score distributions, and sample responses for each of the six questions. Grade yourself against the published scoring guidelines, since the free-response half is where justification and notation carry their weight.

Where GeniusPal fits on a BC syllabus, and where it does not

Start with the boundary, because on a mathematics course it is a real one. GeniusPal works on text you hand it: a set of notes, a chapter, or a review document uploaded as a PDF, a Word file, a PowerPoint deck, or plain text becomes a study set you can be tested on. Images sit outside that line. There is no OCR, so a photograph of a worked problem is a file type the upload declines, and a PDF that is really a picture of its pages is turned away for carrying no readable text. Figures, graphs, and anything you drew by hand inside a document are invisible to it as well.

Inside that boundary, Unit 10 is close to an ideal case. The name and the condition of every convergence test, the standard Maclaurin series, the vocabulary around Taylor polynomials and their error terms, and the parametric and polar formulas in Unit 9 are all text, and all of them are things you have to produce from memory before any computation begins. Turning a chapter of series notes into a question set and answering it without the notes open is retrieval practice pointed at the one unit AB gave you no reps on, and the pattern-matching drill described above is exactly what repeated self-testing suits.

Now the limit that matters most here. Every question GeniusPal writes comes out of the material you gave it, which makes it useless as a source of released College Board free-response questions. On a mathematics exam those past papers, worked in full and graded against the official scoring guidelines, are the irreplaceable part, and no question set will ever mark a justification for you. Let the app carry the memory layer and put the hours it frees straight into released questions.

One feature is worth naming, because BC hands you the raw material for it. Upload one of those released papers as an exam style and GeniusPal reads it for its shape, keeping topic weights, the mix of formats, a difficulty band, and the command verbs it was written in. The questions it generates afterwards still come out of your own notes, in that shape: the notes supply the facts and the paper supplies the style. Three honest limits belong with that. A style is an estimate drawn from one paper and never a forecast of what your own exam will ask. It moves written questions and leaves multiple-choice stems much as they were, so it pays off on Student and Genius, where written mode is available. And a style steers nothing until you have opened and reviewed it, which is the step that catches a misread paper. A free account gets one paper analysis for the life of the account, Student allows ten a month, and Genius thirty.

The plans, so nothing about them is a surprise later. A free account carries 2 study-set generations for the life of the account, 10 questions in each free set, and 2 full sittings of a set once it exists. Paid sets run up to 30 questions: Student costs $14.99 a month and allows 100 generations a month, and Genius is billed annually at $59.99 a year, which works out at $5.00 a month. Quiz mode is available on every plan, while flashcards and written active recall open on the Student plan, and on the paid plans a quiz can be set to a written mix at A few written, Half and half, or All written. The daily review, assembled from questions you have missed across all of your sets, is free and unmetered on every plan.

What the unit table hands you, before the course even starts, is a map of where the year gets hard. Two of the ten units are new ground and sit at 10 to 15 and 15 to 20 percent of the multiple-choice section, three of the units you appear to share with AB carry BC-only topics inside them, and the heaviest band on the table holds the one unit nothing else in your mathematics career has prepared you for. Study in that order, pace against 42 multiple-choice questions and not the 45 an older book will show you, and BC stops being AB with a surprise at the end of it.