Find the number of correct answers on your test results sheet for each of the five subject tests. This will be on a scale of 25 questions for each subject.
Compare the number of correct questions to a GED conversion chart (see the references) in order to find the score of each subject test. This will be on a scale of of 800, where 200 is the low score and 800 the highest.
Compare the scores of each of the subject tests. Note that scores in language art/ writing and mathematics must be at least 420 and 450 respectively for a passing score, and all other scores much be at least 410 to pass.
Add together the scores for each of the five subject tests using the calculator in order to find the total combined score for the GED test.
Divide the total combined score by five (using the calculator) in order to find the average and actual score for your GED test. A 450 is the minimum passing score.
Compare this score against an interpretation of the GED scores in order to find the grade point average to which your GED translates (see the references for "average GED scores). According to Test Prep Practice, a score below 300 translates to a 0-0.9 GPA; 300-400 to a 1.5-1.9 GPA; 400-500 a 2.0-2.9 GPA; 500-600 a 3.0-3.4 GPA; 600-700 a 3.5-3.7 GPA; and a 700-800 a 3.8-4.0 GPA.