The highest IQ exceeds 200 and is reserved for those categorized as an unmeasurable geniuses. On the other end, the lowest IQ can go below 20 and this falls under the category of profound intellectual disability.
The average IQ ranges from 85 to 115. An IQ is in the genius range when it hits 140 to 145 and only every one in every 400 people have an IQ at this level. Albert Einstein is one of the smartest men in history and his IQ was 160. Those who get invited to join the genius society of Mensa have an IQ in the top 2 percent.