Yes. Typically, there is a 1.5-size difference. A US Women's 8.5 is roughly equal to a US Men's 7.
European sizing is based on "Paris Points," where each point is 2/3 of a centimeter. This is why EU sizes are higher numbers (e.g., 42, 43).
Different brands use different molds. Nike often runs slightly narrower, while Adidas can run wider. Check the JP/CM size for the best comparison.
This represents the actual length of your foot in centimeters. It is the most consistent measurement across all global brands.