Michio Kaga’s height was estimated by scaling him next to Roxanne, a female character in the anime. The Slave Harem Fandom mentions Roxanne to be “similar in height” with Michio, saying that she is approximately around 160cm. However though, the fandom doesn’t really mention Michio’s height in his character profile page inside the Fandom.
If this is the case, then we assume Michio should also be approximately around 160cm tall, however, for a much more comprehensive height analysis, we will visualize the height difference between Michio and Roxanne using this IMDb link containing a photo with both of them standing side by side.
If we give Roxanne a height of 160cm, it is actually pretty clear that Michio is taller by a few centimeters compared to Roxanne. By using Hikaku Sitatter Height Comparison Chart, we were able to come up with the idea that Michio is around 4cm taller than Roxanne, therefore, we shall give him an estimate height of 164cm.