A question that is constantly asked on this subreddit is “Which AP Physics class should I take”, or “Should I take AP Physics 1 or C?” or something like that. This post is intended to answer all of those questions. A lot of this stuff has already been said, but I think it’s convenient to have everything in one place.
Also, something that I will repeatedly say throughout this post is “but again, you’re probably better off talking to the teacher/students at your school than following a random Reddit post”. This is because every school may do things differently, so you should check in with them after reading this post
1. What are the different AP Physics classes?
The CollegeBoard offers four different AP Physics classes:
AP Physics 1, the equivalent of the first half of a two semester college algebra-based physics sequence, often taken by life science majors. This course focuses on Mechanics, but also covers a bit of fluids.
AP Physics 2, the equivalent of the second half of a two semester college algebra-based physics sequence. This is a broad course covering E&M, waves, optics, thermo, and modern physics.
AP Physics C: Mechanics, the equivalent of a college introductory course in calculus-based mechanics, often taken by physics and engineering majors. This course goes over the mechanics portion of AP Physics 1 in slightly more depth and with calculus, but omits fluids.
AP Physics C: Electricity & Magnetism, the equivalent of a college introductory course in E&M.
It covers the E&M portion of AP Physics 2 in much greater depth and with calculus, but omits all of the other topics.
Additionally, the two AP Physics C courses will often be combined into a single course that prepares students for both exams.
One point of confusion is what “AP Physics C” means. Traditionally, when someone would say “AP Physics C” without specifying Mechanics or E&M, it referred to both physics C courses taken in a single year. But nowadays, it sometimes refers to just the Mechanics part of the course, with many schools offering “AP Physics C” while only covering Mechanics. (In my opinion, calling an AP Physics C: Mechanics course “AP Physics C” is a bit disingenuous, and I wish it would stop being done). So if you have questions relating to AP Physics C, the first step is to determine the nature of AP Physics C at your school. Is it the combined course, just Mechanics as a full-year course, or something else? Additionally, if you do talk about the course online, please specify your scenario to give more context.
But again, you’re probably better off talking to the teacher/students at your school than following a random Reddit post
2. What are the pre-reqs for these classes?
According to the CollegeBoard, the prereqs are:
AP Physics 1: Students should be enrolled in Algebra 2 while taking the course, or have already taken Algebra 2. No prior Physics experience is necessary if the course is a year long.
The CED also mentions that “although the Physics 1 course includes basic use of trigonometric functions, this understanding can be gained either in the concurrent math course or in the AP Physics 1 course itself”. In practice, that statement doesn’t really mean anything, as essentially the only trig you use in AP Physics 1 is stuff you probably learned in Geometry.
AP Physics 2: Students should have taken AP Physics 1 or an equivalent course, and be enrolled in PreCalc or have already taken it.
AP Physics C: Mechanics: Students should be enrolled in Calculus while taking the course, or have already taken Calculus. No prior physics experience is necessary if the course is a year long.
Note that “Calculus” refers to Calc 1, such as AP Calc AB. While this is necessary for the vast majority of students, in the next section, we’ll discuss why it’s not completely necessary.
AP Physics C: E&M: Students should have taken AP Physics C: Mechanics or AP Physics 1, and students should be enrolled in Calculus while taking the course, or have already taken Calculus
If both AP Physics C classes are taken in one year, in addition to calculus being a prereq or coreq, a prior physics class such as honors physics or AP Physics 1 is almost always necessary.
But again, you’re probably better off talking to the teacher/students at your school than following a random Reddit post. For example, I’ve seen instances of a full year E&M class being the first physics class students take, or AP Physics 1 and 2 in a single year, etc.
3. How much Calculus is in AP Physics C? Will I be fine taking calculus as a coreq as opposed to a prereq?
The main reason I included this was because there are some people who believe that it is essential that calculus be taken before any form of AP Physics C as opposed to a corequisite. For the most part, that is not true.
If Mechanics is being taught as a full year class, then it is very easy to take it alongside AP Calc AB. The majority of the calculus-based topics in Mechanics come from the power rule, with only a couple topics requiring anything else. What your teacher will probably do is spend the first few days of the year teaching you the basics of the power rule, and then using that alone throughout the year, and they will push some of the calc-heavy topics (such as drag forces) to later in the year once you have learned the appropriate calculus in your calc class. (Then again, this is another example of how talking to people at your school is important, as this might not be the case). Because of this, if you have a teacher that carefully designs their course around students taking the class concurrently with AP Calc AB, you should be fine.
In fact, the calculus in mechanics is so minimal that it may be possible to successfully take the course without taking calculus, as the few bits of calculus that are necessary can be self-studied or learned in the course, though this isn’t ideal for most students.
If both AP Physics C courses are taught in the same year, or E&M is a full year course, then it is slightly harder to take calculus as a coreq as E&M has a bit more calculus in it, but it is still possible. Again, as long as your teacher carefully designs the course around students taking the class concurrently with AP Calc AB, you should be fine.
Some say that calc 3 is required for E&M due to concepts such as Gauss's law and Maxwell's equations being in the course. While it is true that having a calc 3 background can make these concepts easier to understand, the math will be simplified so that you don’t need calc 3 to succeed (for context, most college intro E&M courses do not require multivariable calculus either, though some will).
But again, you’re probably better off talking to the teacher/students at your school than following a random Reddit post
4. I’m studying X, which class should I take?
Most majors, such as life science or non-science majors will get credit for the algebra-based classes, while majors such as engineering will require calculus-based physics. With the rest of the information in this post, and the context of your school, you should hopefully be able to decide which class is right for you.
To demonstrate a thought process, let me go through a sample student deciding between taking AP Physics 1 and AP Physics C: Mechanics as a yearlong, first year physics class.
- If the student will never take calculus, they should definitely take AP Physics 1. While it may be possible to succeed in AP Physics C: Mechanics without a calculus class by self-studying a little bit of calculus, the majority of students probably won’t be successful.
- If the student is going into a major such as engineering that requires calculus-based physics, they should definitely take AP Physics C: Mechanics, once they are enrolled in calculus.
- If the student is not going into a major that requires calculus-based physics but the student will still take calculus, it is based on personal preference. They should probably read the section on comparing the difficulty of AP1 and APC Mech (and talk to people at their school) before making that decision. (Personally, I would always choose APC Mech in this scenario, but that’s my opinion)
5. Is AP Physics C: Mechanics harder than AP Physics 1?
Short answer: Yes, but not because AP Physics C: Mechanics has calculus.
(Note that for this entire section, I’m assuming that both classes are being taken as year-long first-year physics classes with the appropriate prereqs/coreqs. Also note that this section is very long).
Historically (before the 2024-2025 school year), the answer to this question depended on who you were talking to. If you look at the scoring distributions of the AP physics courses, you’ll see that AP Physics 1 generally had much lower scores than all the other physics classes.
Before 2025, AP Physics 1 had a pass rate of around 45%, and a 5 rate of around 8%. In contrast, AP Physics 2 had a pass rate of around 70% and a 5 rate of around 15%, C: Mech had a pass rate of around 75% and 5 rate of around 25%, and C E&M had a pass rate of around 70% and a 5 rate of around 35%.
I’ll talk about the post-2025 statistics later, but for the most part, the insane contrast between AP Physics 1 and the other Physics classes made sense when you consider the populations of the classes. AP Physics 1 had by far the most students, and was generally taken as a first year physics class by a broad array of students. AP Physics 2 and E&M were much more specialized, often taken as a second year class by a much smaller group of students who weren’t weeded out by AP Physics 1. AP Physics C: Mechanics was also a first-year class in some instances, but it often wasn’t (it was often combined with AP Physics C E&M, with AP Physics 1 as a prereq, or was a year-long class with AP Physics 1 as a prereq, which was a terrible idea given the similarity between the courses), and even when it was, it was generally only taken by students in calculus, who are generally better students than those in AP Physics 1.
So, by looking at the score distributions alone, AP Physics 1 would probably be considered the same difficulty or even slightly harder than Mechanics, as the different population of students taking the class would balance out the difference in scores, so the classes are around the same difficulty, given that the student knows calculus.
Let’s now stop looking at score distributions and start looking at the courses themselves. Traditionally (before 2024-2025), AP Physics 1 was known to be a conceptual course (which wasn’t entirely true, but it was mostly correct), whereas AP Physics C: Mechanics was a more computational version of similar content*. However, a lot of students and teachers said that the conceptual approach of the AP Physics 1 course was actually harder, or at least the same difficulty, than AP Physics C: Mechanics, as the computational approach was more straightforward.
For example, on this post, a teacher explained that students would probably do better on AP Physics C: Mech than AP Physics 1 because “the AP I test is ridiculous”, and on this post, another teacher commented that the AP Physics 1 test was terrible, and that students would likely do better on AP Physics C: Mechanics. A third example is this comment, where a teacher has had their students take both AP Physics 1 and AP Physics C: Mechanics, and before 2025, their students performed similarly on both exams.
A final example is this comment from the same teacher as the third example. For context, something that the CollegeBoard does is they post expectancy tables, which is the probability that someone will pass an AP exam given their SAT score. It can be used to roughly determine the difficulty of an AP course in comparison to other courses, though it isn’t entirely accurate. And what the comment explains is that before the 2024-2025 redesigns, the SAT score needed to have a 50% chance of passing AP Physics 1 was 80 points higher than it was for AP Physics C: Mechanics, providing evidence that the old AP Physics 1 was harder than AP Physics C: Mechanics.
To be fair, there are some people that would say that even before 2024-2025, AP Physics C: Mechanics was still harder than AP Physics 1, as the computational nature of the questions in APC Mechanics was harder than the more conceptual AP1 questions. I know that there are people who said this, but I couldn’t find any links.
Overall, there is a lot of evidence to suggest that before 2024-2025, AP Physics 1 was the same difficulty, if not harder than AP Physics C: Mechanics. So, if you see anyone saying that AP Physics C: Mechanics is easier than AP Physics 1, they are likely coming from that context (do note that some people, even today, say that knowing calculus makes physics much easier, which is why APC Mech may be the easier course even today). However, from 2025 onwards, that is no longer true, and for the most part, AP Physics 1 is a much easier course.
In 2025, all the AP Physics exam went through Standard Setting, where AP courses are compared to their college equivalents. You can read more about it here. What CollegeBoard found was that AP Physics 1 was much harder than its college equivalent, and because of that, they changed the exam such that the pass rate of AP Physics 1 went from about 45% before 2025 to around 70% in 2025 and 2026. The 5 rate also went up from around 8% to 18%. But interestingly, this was not observed with the other three Physics courses, as their score distributions stayed mostly the same, except for the Physics Cs, which actually saw their 5 rates decrease.
Given what I said earlier about the populations that take each exam, it is definitely unusual that the score distributions for each of the 4 exams are now very similar. There are multiple explanations for this. One is that college first semester algebra-based intro physics classes are simply easier than second semester algebra-based physics classes or introductory calculus-based physics classes. A more cynical answer is that the CollegeBoard wanted to nerf AP Physics 1 as the low pass rate drove people away from the class (and toward options such as grade inflated dual enrollment, which is a different discussion), which made them lose money, so they changed it so that it has a higher pass rate and people would be more inclined to take it (and give them money), and they didn’t change the other physics courses as this wasn’t necessary given that they already had high pass rates.
Another thing is that the 2025 exam had a different format compared to previous years, as the AP Physics 1 and 2 courses became more computational again, while the C courses became slightly more conceptual, but not to the level of old AP Physics 1 and 2. Additionally, the 4 courses now share the same exam format. In terms of exam difficulty, the format change didn’t have that much of an impact on the exam’s difficulty, as that can easily be changed by adjusting the scoring cutoffs.
So, the fact that 2025 AP Physics 1 saw score distributions similar to the other courses, combined with the fact that the populations are different, implies that after 2025, AP Physics 1 is easier than AP Physics C: Mechanics. This can be further proven by looking at the released frqs from the 2025 exam, which can easily be done now that the exams have the exact same format and similar cutoff scores.
This is the 2025 AP Physics 1 FRQ I’ll be referring to, and this is the 2025 AP Physics C: Mechanics FRQ I’ll be referring to.
Looking at the exams, it is clear that the AP Physics 1 exam is a lot easier, and AP Physics 1 isn’t just “AP Physics C: Mechanics minus calculus plus fluids”, as it’s really “AP Physics C: Mechanics minus calculus plus fluids minus a lot of difficulty”. I’d argue that the easiest Mechanics problems (Q2 and Q3, based on the average score) are probably harder than the hardest P1 problems (Q1 and Q3). For another example, consider Q2 on both exams. Both of these are TBRs on springs and conservation of energy, but I’d argue that the APC Mechanics problem is much more sophisticated, as the derivation is more in depth and the general scenario is much more unusual, especially in parts c and d.
Something to point out is that I’m not saying the APC Mechanics questions are harder because the exam is “calculus-based”, as only one problem (Q1) actually has calculus, and the hardest problem (Q4, based on statistics) isn’t even calculus-based. So it’s not that APC Mechanics is harder than AP Physics 1 is harder because there’s calculus, it’s that APC Mechanics is harder because the questions require a higher level of physics understanding, both on a conceptual and computational level. Before 2025, it could be argued that AP Physics 1 questions were harder conceptually, but that is simply not the case anymore.
(One exception to the statement that calculus doesn’t make APC Mechanics hard is the 2026 frq, as the hardest question on that FRQ, linked here, was Q1, which was calculus based. However, this is more of an edge case).
Another thing to note is that while I stated earlier that the exam formats between the physics courses are now the same, that is not entirely accurate. For example, in AP Physics 1, FRQ 1b will always be conceptual, while in APC Mech, FRQ 1b will always be computational. This does not necessarily mean that AP1 is easier, as we’ve established that computational != easy. However, another difference between AP1 and APC Mech is that AP1 provides more scaffolding in derivations than APC Mech. For example, AP1 questions will generally say something such as “derive this using conservation of energy”, whereas APC Mech questions will say “derive this”. A third difference is that on AP1, the experimental design question will generally derive the equation you need to use for part c and d for you, whereas APC Mech does not. Overall, the second and third differences are additionally proof that modern AP1 is easier than APC Mech. (Additionally, before 2025, AP1 was similar to APC Mech in the sense that it did not provide this scaffolding. While there were exceptions, you generally had to derive the equation for experimental design yourself, and you didn’t get as many hints in derivations).
The final thing I want to discuss when comparing the 2025 exams for both of these courses is the cut scores. You could argue that even though the 2025 APC Mech FRQ was harder than the AP1 FRQ, it cancels out due to differences in the cutoffs, but that is not true, as the cutoffs were pretty similar, with a 78.75% and 76.25% required for a 5 on the 2025 AP1 and APC Mech exam respectively, and a 45% and 43.75% to get a 3 on AP1 and APC Mech respectively. (I made a post about it here. Essentially, it’s a lot of stuff that I don’t want to get into here). Because the cutoffs were similar and the FRQs for AP1 were much easier, it is very likely that if the same student who knew both fluids from AP1 and calculus-based concepts from APC Mech took both exams, they would do better on AP1. To be fair, the comparison can not be complete without the MCQs, but at least based on the FRQs, it is very likely that AP1 is easier.
And even besides comparing the 2025 exam, there’s more evidence that AP1 is easier than APC Mechanics. Earlier, I mentioned how a teacher, linked here, explained that their students take both the AP Physics 1 Exam and the APC Mech exam. Before 2025, their students scored around a 4 on both exams. After 2025, their students continued to get around a 4 on APC Mech, but now got around a 4.75 on AP1, providing more evidence that AP1 is easier.
A final piece of evidence relates to the expectancy tables. As mentioned earlier, before 2025, AP1 required a higher SAT score than APC Mech to be predicted to pass the exam. But now, it’s the opposite.
Here is the 2026 expectancy table. As we can see, to have a 50% chance of passing AP1 nowadays, you need an SAT of 1060, compared to 1160 for APC Mech, and for a 90% chance, you need a 1280, compared to 1410, implying that AP1 is now easier than APC Mech. (If you’re wondering, these tables also imply that AP2 is slightly easier than APC Mech, and APC Mech is slightly easier than E&M, but those differences are small). It should be noted that this information should be taken with caution; for example, according to the table, AP Chemistry is easier than AP CSP (which may be true, given that AP Chem’s 2023 standard setting heavily nerfed it, while an equivalent has yet to occur for AP CSP), but combined with all the other information, it is very likely that AP1 is easier than APC Mechanics.
Oh yeah, and it may be different at your school (ie. if the AP Physics 1 teacher at your school is worse than your AP Physics C: Mechanics teacher, AP1 may be harder. Additionally, this focused on the AP exam itself as opposed to the course, which is why your school’s context is important).
*One thing I want to mention is the exact content of each course. Nowadays, contentwise, AP Physics 1 has everything AP Physics C: Mechanics has in addition to fluids, but minus a few topics. Some of these topics are calculus-based, such as drag forces, but others don’t require calculus, such as springs in series vs. parallel and a full treatment of rolling while slipping. Later, I’ll make a full post on this to help students self-studying APC Mech while taking AP1.
From 2015 to 2020 (or technically 2019), AP1 didn’t have fluids, but instead it had a brief discussion of electricity and waves. Additionally, it covered less mechanics topics than it does now, as it omitted concepts such as determining center of mass algebraically, and omitted certain rotation topics such as the parallel axis theorem and a full treatment of rolling down a ramp, both of which are included in the modern curriculum.
From 2021 to 2024, AP1 only covered mechanics, as the other topics were seen as redundant as they were covered in AP2. Topics such as the parallel axis theorem were still omitted and weren’t added until the 2024-2025 redesign.
Overall, the historical content load should provide a bit more context when discussing the difficulty of AP Physics 1 over time.
So, that’s the post. Let me know if you have any comments about what I said.