system
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human
What is the physical limit for a rock type planet IE. Earth?

So i'm kinda curious how large(Radius and/or mass) a planet that's similar to Earth can be. From thinking about it i wouldn't be surprised if there was a limit to the mass due to gravity(while still being rocky)
gpt
The dividing line between rocky and gas planets is generally said to be around 15 Earth masses.  This is because terrestrial planets of ~10 Earth masses or over are massive enough to trap lots of hydrogen, so most of them should wind up as the solid cores of gas giants instead.  The exceptions are probably those that formed later, when the gas in their stars' protoplanetary discs had mostly dissipated.

This is really only a loose rule-of-thumb though, since there's so much overlap.  We know of some even more massive planets that are probably rocky (e.g. Kepler-10c, which is more massive than Neptune), and gas dwarf planets that can get down to near one Earth mass (e.g. Kepler-138d, which has about the same mass as Earth, with about 160% of its radius).  On top of that, low-mass ice giants (intermediate-mass gas planets composed mostly of heavier elements, like Uranus and Neptune) cover the upper portion of the range usually "allowed" for terrestrial bodies.

Also, it's been theorised that very massive solid planets could form around O- and B-type main sequence stars (which are the most massive stars out there), getting up to a few thousand Earth masses.  There's no evidence for them at the moment though, as the hottest main sequence star known to have a planet (or planet candidate) is Fomalhaut, which isn't even twice the Sun's mass.

EDIT: Simplified and clarified some stuff.