You should choose the usual size.
However, if you have a doubt:
- Place a sheet of A4 paper on the floor with the edge against a wall.
- You or your child should stand on this sheet of paper in your bare feet, with your heels against the wall.
- Make sure that your heels are in contact with the wall and that your feet are flat on the floor.
- Draw a line on the sheet at the end of your toes.
- Measure the distance between the edge of the sheet and the line you have just drawn (in centimetres).
- Enter this measurement into the box below and your size will be displayed automatically!