According to the GED Testing Service, passing grades are based on scores, not percentages. Although some states set their own passing standards, most follow the Testing Service standard, which is a combined score of at least 2250 for all tests.
Florida's Community Technical & Adult Education indicates that the GED has four subtests: Reasoning Through Language Arts, Mathematical Reasoning, Social Studies and Science. The passing 2250 score is based on an average score of 450 out of 800 for each subtest. An "average" score indicates that some subtests may be higher, while others may be lower. High scores on one subtest are able to compensate for scores lower than 450 on another subtest. However, students do not pass if any individual subtest score is less than 410.