I see where the macro comes from, how large are red/white blood cells for comparison?
Sort of like asking how large a half filled water balloon is, it can have significantly different size depending on the environment. That said the most commonly given "biology 101" figures for the major types tend to be something like (in micrometers) Macrophages: ~21 Neutrophil: ~12 (more variation here often given as a range of something like 10-14) T, B, and Red Blood Cells: ~7 (all fairly similar in average size)
I'm not sure where the idea normal human macrophages are 40+ microns in size came from, but that's totally inaccurate.
