UK schools use A-levels (2 years of the same course, kind of like an AP test I suppose). Colleges usually expect 3 A-level scores, the highest being A, then A, B, C and so on. So for their admissions to certain majors(courses as they are called there) they usually post their score requirements/recommended requirements. so like, “For physics: AAA, in physics and higher/upper maths” (this example would be for a very competitive school, as getting an A is near perfect) (which means that among the 3 A-levels you’ve taken at school for two years, they expect a grades of A, A, and A. and they expect that you took the physics A-level and upper maths A-level.
In the UK universities’ international admissions requirements, when equating to US educational scores, they usually require you to have taken at least 3 AP tests with scores of 5. (depending on the competitiveness of the university they may ask for just a score of 4.) As for SAT scores, they usually want above 600 in each section. The AP scores are what’s important here. Sometimes they mention GPA, and usually they want above a 3.0 or 3.5 depending on the selectivity of the university. They don’t care about extracurriculars. During your admissions essay (you apply through UCAS, sort of like a common app equivalent i suppose), you mostly write about why you chose your particular course of study (aka major).
University in the UK is different than in America. These A-levels I speak of, it’s kind of like junior college. During their first two years of ‘high school’ they take AS-levels (I think that’s what it’s called). Then when they get to their 3rd and 4th years, they choose 3 A-levels to take. They take the same 3 courses for 2 years. It’s more specialized that way. In a way, this prepares you for your course/major. By the time you get to university, you will typically spend just 3 years there, but there is generally no general ed classes or anything of the sort. It’s just 3 years of your course/major. So it’s a great system if you already know for sure what you want to major in and are certain that you won’t want to switch in between. It’s difficult to transfer in the UK, it’s not that common.
So yeah, there’s some extra information about the reasoning behind the US requirements for UK schools and how they equivocate to their schooling system.
You’re scores are perfect. Precisely what a top student’s admission profile would look like.
Other note: when you apply (through UCAS), for Cambridge and Oxford you have to apply before October 31st (this date might be different if they’ve changed it). You can also apply to other UK schools at the same time by that date. You’ll get an update from the colleges giving you a “conditional offer” which means that you’ll be accepted based on whatever terms a specific uni gives you (say, getting AAB on your A-level exams). Seeing as you already met the requirements, perhaps they’ll just give you a unconditional offer which means you’re basically accepted (but you should still check to see if they ask anything extra of you).
Correction: Most UK schools don’t care about extracurriculars, except for Oxbridge (Oxford and Cambridge). They DO expect more from their applicants than just passing the requirements. They already have high requirements to begin with so if you have any amazing stories about how you saved lions in Africa or anything like that, feel free to write about it in your essay. (That’s not to say it’s impossible to get in, you just have to wow them). I think the fact that you already have like 9 AP tests planned, with no score lower than a 4 might be impressive enough to them. Just articulate yourself well and you should do find. Show that you’re a scholar.
Cambridge is very “good” and “wholesome” (for lack of better words). They like to see extracurriculars that show you’re a great kind person. In addition, of course, to having excellent grades. Oxford on the other hand is more focused on the academics alone (but that’s not to say that they don’t expect a lack of ECs).
Another thing of importance for UK schools when it comes to international students is that you can demonstrate funding. I think that’s part of the unconditional/conditional offer thing. Proof that you have funds to support yourself, ect. I’m not too savvy on this though, it might be a part of the application on UCAS or something additional that the university itself will ask of you to verify somehow. Being able to get a VISA, ect.
Good luck!
EDIT: yes as others have mentioned there is an interview and you have to take an exam when applying to STEM. i think it’s usually a math and physics test or something. probably just math if you’re just a maths major. you have to do that in the US though if you can. cambridge has a website where you can search for locations near you that offer the test. it won’t always be at another school, for example the one near me was a language studies center or something like that. you have to arrange to take that test, just follow the instructions on the cambridge website. they have practice tests you can take a look at. this is definitely one of the most important factors beyond just grades. this and the interview.
during the interview they just talk about the course you’re applying to, they try to ask you questions to try to understand how you think, your logic and what not. it’s actually pretty cool if you ask me. the questions might just be like maths problems or more logical stuff. philosophical. they just want to know if you can think, and if you can think, are you exceptional at it? are you the kind of scholar they’ll want at their college?