1. Stand upright on a firm surface with your heel against the wall and a sheet of white paper taped to the floor, and level it against the wall under your foot.
2. Ask someone to mark the longest part of your foot (known as heel-to-toe length) on the paper with a pencil or pen, or measure yourself if necessary. Repeat the process with the other foot, as the sizes between the two may be different.
3. Use a ruler to measure the length from heel to toe that you marked for each foot.
This is a rough conversion chart to help you find your size.