system
Given the following post, respond as if you're commenting on Reddit:
human
How big can black hole get ? Is there a limit ?
gpt
If by "big" you mean spatial extension, there is really no way to answer this question.

The black hole itself is a singularity, meaning it has no volume whatsoever. Thus, the size of black holes is mostly measured by the radius of its event horizon (or *Schwarzschild radius*).  

The size of the Schwarzschild radius is proportional to the mass of the black hole. Since the mass of a black hole has no upper limit, the "size" of a black hole could, theoretically, be arbitrarily large.