The term "natural waist" refers to the narrowest point between the bottom of the rib cage and the pelvis. You may sometimes need to know your natural waist measurement to ensure that you buy the correct size clothing. Also, according to the website of the Centers for Disease Control and Prevention, your waist measurement is an indicator of whether you are at a healthy weight. A man whose waist measurement is greater than 40 inches or a woman whose waist measurement exceeds 35 inches has a greater risk of developing Type 2 Diabetes, high blood pressure and other obesity-related health problems, according to the CDC. Measure your own natural waist using a cloth tape measure — the type used by seamstresses and readily available in a store's sewing department.
Remove all your clothing except your underwear. This allows you to measure around your bare waist and not have your measurement distorted by clothing.
Find the tops of your hip bones. The natural waist is just above your hip bone.
Stand straight and relaxed. Exhale, but do not suck in your abdomen or tighten your stomach muscles.
Hold the tape measure with one hand at the end that shows zero inches. Wrap the tape measure around your waist, just above the tops of your hip bones, until it meets the zero end.
Look to confirm that the tape measure is in a straight line all the way around your waist. The tape must fit snugly but not too tightly against your skin.
Look at the measurement on the tape measure where it meets the zero end. This is your waist measurement.