Okay! Waist measurement is important and needs a lot of accuracy and precision. All you have to do is to consider your circumference of your waist. For this you can use a tape or anything like that and all you have to do is to circle the waist just like a belt would do at the natural or usual waist line. Your natural waist line is located below your rib cage and at above your belly button. If still you are meeting troubles whilst finding your correct waist line, all you have to do is to bend to a side, you’ll see a crease formed. This crease is your natural waist line. Avoiding sucking in your stomach because this will lead to a false or less precise measurement , source. Another point that can help you is that while using the tape; note the point where both ends of the tape meet. The point of this meeting is your actual or natural measurement of waist. Another smart move is to double check your measurement. Repeat your method to ensure the precision and accuracy of your measurement.
Generally, experts report that the waist line measurement for women should be less than 32 inches or 81.3 cm and for men it should be less than 38 inches or 96.5 cm.