I keep seeing wildly different claims about Elon Musk’s IQ ranging from 150 to 180 depending on who you ask. I am pretty sure he has never publicly taken a validated IQ test but people state these numbers with total confidence. Where do these estimates come from and how seriously should anyone take them?
Every specific number you see attached to Elon Musk is fabricated or at best a very rough retrospective estimate with enormous uncertainty 
There is no public record of Musk ever taking a validated standardized IQ assessment and publishing the result. The numbers that circulate online are either invented by clickbait sites, derived from informal estimates based on his achievements and educational background, or extrapolated from the kind of historiometric methods used for historical figures. None of those approaches produce reliable precise scores. What we can say with reasonable confidence is that Musk shows strong evidence of high general cognitive ability based on his demonstrated capacity across multiple complex domains, engineering, finance, physics, manufacturing, and software. That kind of breadth is genuinely g loaded and suggests well above average intelligence. But translating that into a number like 155 or 168 is not science, it is speculation dressed up as precision 
The irony is that the actual number matters less than people think 
Beyond roughly 130 the marginal predictive value of additional IQ points for real world achievement diminishes considerably. What explains Musk level outcomes is high g plus extraordinary drive, risk tolerance, and domain knowledge, not a specific three digit number