The average IQ of a chess grandmaster is estimated to be around 130-135. Chess grandmasters have a combination of strategic thinking, exceptional analytical abilities and strong memory recall.
A person with average IQ is expected to reach a maximum rating of about 2000 in chess. Strong grandmasters with a rating of around and over 2600 are expected to have an IQ of 160 plus. The strongest grandmasters of the day with their ratings hovering around 2800 are expected to have IQs around 180.