Most adult pull-up diapers are available in 4 to 5 sizes: small, medium, large, x-large, and xx-large, using waist size as a standard measure. However, the method is not ideal for many consumers to order the correct size since body mass and shape are essential factors in getting a comfortable diaper fit. Therefore, the easiest and most effective way to get a comfortable fit is to measure the circumference of the widest part of your waist and abdomen. Then, use the larger of this measurement pair to choose your adult diaper size. Since brief sizes vary from brand to brand, it is best to double-check by reading their adult diaper size chart. Also, a loose-fitting diaper could lead to leaking in the leg area. So, it would help if you started with the snuggest comfortable size and progressed upward from there.