As a now graduate student in philosophy, having done a triple subject undergrad in politics (lots of analytic/math work), philosophy and psychology and then completed a law degree, I personally don’t think calculus is useful and I don’t think a math class with proofs is helpful at all.
Personally, I took AP calc in my Jr. year of high school and then never went near another formal math class ever again. Formal logic requires an understanding of abstract reasoning, but I do not think that Calc provides a good grounding in this particular type of abstract reasoning. Philosophy students tend to perform the best on the LSAT (though math students also perform very well).
I don’t think that a philosophy major should have to take math - as someone who does legal philosophy, there is absolutely nothing I could use math for, certainly not calculus.
This isn’t to say that math cannot be helpful to a philosophy major. This is particularly true in relation to which area of philosophy you intend to study. For example, a philosopher of mind typically has an excellent understanding of psychology and statistics, the latter being of paramount importance in understanding psychological data.