The ski boot is an important part of the ski equipment. It acts as a link between the skier and the sports equipment. The ski boot automatically puts the skier in an optimal basic posture so that all movement impulses can be transferred to the ski. The ski boot thus provides direct power transmission, stabilizes the skier and, incidentally, keeps the feet dry and warm. Accordingly, it is important that a ski boot fits perfectly and encloses the foot firmly without pressing. The most important criterion when buying a ski boot is the boot size. This is given as the Mondopoint. The Mondopoint is the foot length in millimeters, measured from the heel to the tip of the foot plus 5 millimeters for clearance. The standard is used by many manufacturers such as Head, Salomon, Tecnica or Dalbello, but even these sizes can vary slightly.