I selected 22.5 because there was no S size available during size registration, but I think it's around 22.5-23 cm. It was a little big for me, as I usually wear 22-22.5 cm. I wore it once or twice after purchasing and then stored it in the closet. There are some stains from being stored for several years, but they are not very noticeable because the fabric is white beige. There are stains and wrinkles on the heel. Please check the photos and consider before purchasing. The heel is 6.5 cm.