Luna seems to be the first main Yu-Gi-Oh! female that doesn’t have her most noticeable physical feature being her chest. Instead, (based on the first picture) it is her legs. This made me wonder how tall Luna grew to be and here is what I decided:

For starters, Leo and Luna look to be about the same height. Since there’s a good full body shot of Leo in the second image, we can use this to help too. Just like with Luna, Leo has extremely long legs, and it must run in the family.

Using the first. second and third images, both Leo and Luna‘s hips are way higher than the seat height is (the lowest portion of the bike where you sit).

The average for a motorcycle is 28-32 inches. However, both Leo and Luna’s legs appear to be much longer than that, so we can say that the seat height is much more than that too. 37 inches seems more than fair. Include the extra height of Luna’s legs (up to just below the red line in her outfit) and her lower half is about 44 inches (which makes sense, since both of their lower halfs take up over half their height).

For the top half, we can use the last picture. The average height of a woman’s head is 8.5 inches (not including hair) and nothing about Luna’s head implies it’s any different. Measuring, it’s about 3.5 heads, so (8.5*3.5=about 30 inches).

30+44=74 inches, so Luna and Leo both grew to be about 6′2″ or about 188cm tall.