Choosing the right shoe size for men's cycling shoes is an art in itself. In general, men's cycling shoes should fit as tightly as possible. However, they must not pinch anywhere. Most sports shoes for cyclists run a little smaller than you are used to in casual shoes for men. Therefore, always pay close attention to the measurements and try on your favourites.
If you want to measure your feet, it is best to do so at the end of a training session. This is because your feet are pressed slightly flat by the load and are therefore wider than normal. Exactly the same happens in your men's cycling shoes. This small but subtle difference should therefore be taken into account when choosing the right size.