To get the correct and exact size belt, measure the waist/belt on top of clothing regular sewing centimeter. The obtained value is the size of the belt or order size. Simple and convenient. But if centimeter at hand was not, then you are quite successful you can use old pants that you wear and which feel comfortable. This is very important - the pants don't have to press in the waist and hips, otherwise they will not fit.
If you find any pants in your wardrobe, feel free to get down to business. It's very simple: in the same measure centimeter belt keeps pants.
Remember the value that you get. This is your size, which you can use when selecting a belt. Given that most of the belts are now universal, meaning you can manually adjust the girth and waist size, your size has only a conditional value. You will need it in the case when you choose exclusive strap which can be adjusted independently. Or in the case where it is sewed to the suit, pants or skirt. Now this is a common trend.
Of course there is a rather complex way of computing. Measure your height, weight, and volume shoulders. Based on the available values, according to a special standardized table, which again is freely available on the Internet, compare them with the size of theAMI.