Place the end of a measuring tape against the wall and roll it away from the wall

Place one bare foot onto the tape measure firmly against the wall and your longest toe on the tape measure

Take the measurement where your longest toe reaches (in mm)

Do for the other foot too!

Lay a tape measure on the floor and position it so it lays under the 2 bones on either side of your foot as pictured

Wrap the tape around the foot snugly but not too tight - do not pinch the skin!

Take your measurement where the tape crosees over (in mm)