Find your GRE scores and add your verbal reasoning and quantitative reasoning scores together. You will not need to use your analytical writing score.
Compare your combined GRE score to the average score, which is around 1035. If your score is higher than 1035, your IQ will probably be higher than the average. The average IQ of people who take the GRE is 115.
Calculate your IQ from your combined GRE score by multiplying your GRE score by .085 and then adding 26.8. So if your GRE score is 1035, you multiply it by .085 to get 87. 975 then add 26.8 to get 114.775. This equation estimates your IQ to be between 114 and 115.