 The total number of 2018 high school graduates taking the ACT was 1,914,817.The ACT measures high school students' general educational development and academic readiness to complete first-year college-level work.For the tested students from the high school graduating class of 2018, 38 percent met ACT's College Readiness Benchmarks in at least three of the four subject areas the ACT tests—English, math, reading, and science.