The correct size of the belt is when the tongue of the buckle is inserted into the central hole. In a 5-hole belt, the tongue is inserted into the third hole.
You can find out your size in three ways.
Measure an existing belt
This is the most accurate way. Take your old belt with a standard buckle (with a tongue). Measure the distance from the edge of the buckle frame to the hole on the belt, into which the tongue was usually inserted. This value in centimeters is your size.
If the old belt has a non-standard buckle – for example, with a holster button or clamp – find the point for fixing the belt, measure the length from the fixing part of the buckle to the point of fixing the belt.
Measurement of the waist with a flexible centimeter tape
For a more accurate measurement, measure the trousers or jeans with which you will wear the strap. Pass the centimeter belt into the belt loops. Fix the most comfortable tension of the tape, it should be the same as for the future belt. Note the size value.
When making the belt, your size will be counted from the edge of the buckle frame, since in this area there is a point of fixation of the belt. It is not recommended to use a roulette instead of a centimeter/inch tape – the measurement will be inaccurate.
The size of the jeans
The least accurate way. If there is no possibility to take a measurement from an old belt or from a waist, find out the size of jeans in format W L (34х36, etc.). Take the first value (W) add to it 5, multiply by 2.54.
For example, the size of W is 34. Add 5, get 39. Then 39 multiply by an inch in centimeters 2.54, we get a belt size equal to 99 cm.
The value is inaccurate, because the sizes of jeans of different brands may differ. The error of the final result can reach up to 5 cm.