Black holes warp space to the point that countless billions of planets can fit into a fairly normal "size" black hole.
Therefore the concept of "measuring" a black hole can be a nonsense. Inside it is billions of large things. Outside it, it might be a fraction of a light year across. And yet all that matter is crushed under its gravity and becomes nearly a point mass.
When your measuring system is reliant on getting a ruler and putting it somewhere, it all becomes a nonsense under space-time itself warping to the point of galaxies of objects fitting on the head of a pin, which from a distance just looks like a black hole in the middle of a galaxy.
Actual scale here is variable, indeterminate, dependent on the observer, and - in a lot of cases - unknown.