SAT Subject Tests: Math Level 2

Is it better to take the Math Level 2 test after completion of Algebra 2/Trigonometry, Precalculus, or while taking AP Calculus BC?

Best after precalc if the timing works for you. Not hard to study up on concepts after that (e.g. when taking calc)

I would take it right as you are finishing precalc (May/June).