39/42 (with hope for a 42/45, but don’t take those bonus points for granted like I did!) is adequate for these or any schools, but it’s not enough to help you much either. For Princeton especially you’re near the bare minimum for an unhooked applicant. That Math and Physics are your major weaknesses is the main issue. I know secondhand how difficult Math HL is, but a 5 (it depends on how your school writes transcripts, but I’ve generally seen this translated to a C or low B) is a dangerously soft mark for top schools, especially math-oriented ones like Cal Tech whose applicant pool is brimming over with math and science wunderkinden.
For reference, I was admitted to the University of Chicago (EA) with merit money and Dartmouth, and rejected at Harvard, with a 2360 SAT and the following marks:
HL Economics – 6
HL English – 7
HL Philosophy – 6
SL Maths – 7
SL Physics – 7
SL Spanish, ab initio – 7
2 bonus points, for a total of 42/45
Among my classmates, I’ve seen the following (obviously, this list is going to omit things, like safeties or embarrassing rejections, that people didn’t mention, and sadly ):
42/45: Accepted at Stanford, Chicago, Cornell, waitlisted Harvard, rejected Dartmouth, Columbia and Yale (My debate partner, so of course his EC situation was stellar (;. Also didn’t apply anywhere early, leading to unneeded stress; fortunately, the shotgun approach at regular worked out for him)
43/45: Accepted conditionally for history at Oxford; needs to maintain a 7 in his HL history class and a 41 overall to not get rescinded.
44/45: Accepted at Yale (ED) and a prestigious full-ride scholarship at his home state’s flagship.
44/45: Deferred, then accepted at Princeton (SCEA, legacy)
All of the above sported excellent ECs and would have had interviews and essays ranging from “run-of-the-mill but solid” to “inspiring tear-jerker”. No predicted 45s that I know of at my school, so these applications and a few others represent the cream of the crop here – if your school tops out at 41, then a 41 will of course look better. The only person I know of going to a top-ten school with less than 40/45 is a recruited athlete headed for Princeton.