Two things are extremely important when shopping for shoes online – you should follow the shoe manufacturer's table of sizes and carefully measure the length of the foot, or insole of shoes that you feel comfortable in. Follow these things and you'll significantly increase the probability of choosing the correct size and purchase satisfaction.
CHOOSE ACCORDING TO THE INSOLE OF YOUR FAVOURITE SHOES
Measuring the insole (shoe insole) is the best known and easiest method when buying new shoes. However, it also has its pitfalls, so take it as a guide only.
Why? The insole sometimes bends at the toe or heel of the shoe, therefore reducing the foot's inner space. The inner space of the shoes can also be reduced by a thicker insole. On the contrary, thanks to a thicker insole, longer and wider shoes can suit people with shorter and narrower feet, as this results in the shoe fitting better.
Ideally measure the insole in your favourite shoes and orient yourself according to its length when choosing the size of new shoes.
INSOLE LENGTH (SHOE INSOLES) LOAP = FOOT LENGTH + A 12 MM EXCESS
When choosing the size of the shoe, pay attention to the 12 mm minimum excess. (Note: The excess is the free space in front of the toes and behind the heel that's necessary for the free foot movement.) With a smaller excess, the shoe will squeeze you when you walk and there's a risk of unpleasant blisters / deformations of toes or feet when worn over a long period.
The LOAP size chart is constructed so that the stated sizes in millimetres determine the insole length. The length of a LOAP insole is the total length of the foot with a 12 mm excess. Therefore, don't add excess to the insole of LOAP shoes.
For example: For size 36, the insole is 230 mm. After deducting the excess 12 mm, the maximum length of the foot is 218 mm. If you have a longer foot, you should consider size 37.
Unfortunately, it isn't possible to measure every single shoe when you consider the amount of footwear that LOAP produces and sells. Therefore, in relation to the size chart, there may be a slight inaccuracy of +/- 4 mm (half a number), which you should take into account when choosing shoes. (For example, with regard to children's shoes it can be only 2 mm, for larger sizes more.)
TIP: If you want orthopaedic insoles in your shoes, always try shoes with them in. Orthopaedic insoles are usually taller and different in shape than commonly used insoles.
PAY ATTENTION TO THE SHAPE OF THE TOE, EDGE AND HEEL COUNTER
In addition to the uniqueness of your feet, the choice of comfortable shoes is complicated by the fact that each manufacturer uses its own shoemaker's hooves. Shoes in one size, but therefore, they fit you differently from different manufacturers - they are shaped differently in width and height, padding and flexibility. When choosing an insole from another brand of shoes, you may feel comfortable in the shoes even with a larger/smaller size.
Therefore, pay close attention to the shoe toe shape when choosing shoes. Sometimes it doesn't have to copy the outline of your foot or it's rounded so that the longest part falls on its centre. Then what can happen is that the big-toe, which is on the side, may have less space.
When measuring the insole length, the edge of the sandal is also problematic, which remains unused, so the foot space is usually smaller than the shoe's total length. Therefore, don't include the edge in the insole measurement.
In closed shoes, the heel can be offset so that the shoe's usable interior space is smaller. (Note: The heel counter is inserted between the back and the lining of the shoe. Its purpose is to keep the heel in the correct position and help maintain the correct shape of the arch.)
THE PROPERTIES OF FOOTWEAR CHANGE WITH USE
Winter footwear (insulated with "fur", fleece, foam, etc.) is fluffy when purchased, but with long-term use, the inner padding will reduce the volume and increase the foot space.
Also, too intensive or inappropriate use, careless putting on or insufficient care and maintenance will spread the material and construction of the shoe to a width and length after some time, seams or gluing may release. The insole or padding may also become deformed.
Source From：https://www.loap.eu/hints-and-tips/how-to-choose-the-correct-shoe-size/
