Cloud Zero uses a unisex design. We recommend sizing based on the length of your foot (IN/CM).
How to measure your foot
1. Put your heel up to a wall (your biggest foot).
2. Put your bodyweight on the foot, and place a book against the longest toe.
3. Remove your foot and measure the distance between the wall and the book.
Apply the length of your foot to the sizing chart above. For example: If your foot is 25 cm / 10.04 in, you should pick size EUR 40 / US 9.