system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do men have more blood than women of a similar size?

I had donated blood recently and was curious as to how much blood my body has. So I googled a blood volume calculator for a rough estimate and noticed that a man of my weight and height would have slightly more blood than me according to the calculator.

Edit: This got way more attention than I thought it would. And I want to thank everyone for their comments, they are very informative.
gpt
1 - blood is inversely proportional to body fat percentage. And on average females have more fat then males at the same weight and height
2 - menstruation causes women to lose some blood, that needs to be replaced
3 - it has been shown that higher levels of  testosterone causes more blood production. (And faster clotting times)