or 21.4 PrepScholar PrepScholar average ACT composite score the average composite ACT score was 21 the average composite ACT score was 21 or 21.4 In 2014 the average composite ACT score was 21 average nationwide score is 21 average nationwide score is 21 or 21.4 the average composite ACT score was 21 average nationwide score is 21 average nationwide score is 21 PrepScholar or 21.4