Please READ how to measure your waist The Sleep Waist Trainer is perfect for waist training when sleeping or wanting extra support day or night.  Swipe through the photos to see the size chart. How to measure scroll down. Sleep Waist Trainer can be worn anytime.  Adjustable and convertible straps offer versatility, while sleek shaping fabric works invisibly “backstage” to ensure your style gets all the applause. How to pick your size.   A shaper is an undergarment that is not refundable and has no exchanges.  Includes a nutrition card & workouts for best results. It runs small if you compare the product size to your clothing size.  I recommend measuring yourself around the belly button. What to do when in between sizes and wondering if you should size up or down? Size up IF you are NOT measuring your waist with tape. If you pick a size based on your current clothing size, then size up. For example, if you wear a size 10, size up to XL. But I recommend using a tape measure and going by your waist in inches.  There are no refunds for the body sleeper due to its being an undergarment.  Measure the widest part of your nude belly to find your actual size.  For example, if you are 33.1 inches around your belly button, size up to XL. If you size it down & it fits tight: You will be motivated to follow the included meal plan & work on your body to fit into the smaller size. The in-between measure can be confusing. I suggest sizing down because, eventually, you will need to size down anyway.    It's best NOT to compare the cute shaper to your clothes  Provides firm control and shaping Best to wear for 4+ hours OR overnight It controls the entire tummy and back and can be a post-surgery garment. Don't expect thighs to be tight. They don't do anything.Adjustable straps It has an opening for a bathroom Wear with your bra to create the shape you desire Ultra-flat front zipper closure Wide, supportive band to wear strapless Unique design to define the waistline Designed to lift the rear It hits at the upper thigh with lace trim Hand Wash / Hang Dry Imported Do not bleach, no iron, and don't wring Please don't expect it to be tight like other products. This should be comfortable, not tight to move organs.   It is not made for exercise, but you can workout when wearing it if it makes you happy.   How to measure yourself: WAIST It is measured on the navel or slightly above HIPS Measured by the widest part. Remember that the legs must be together. If you have pants on, lower them to your knees. BUST The contour is measured just below your breasts and around your back. It can be done with the bra on. HEIGHT Measured with a straight back, feet together and head aligned. It is recommended that another person take this measure for you. WEIGHT It is recommended that you weigh yourself in the morning on an empty stomach. When using the scale, take off shoes, clothes and anything that carries weight.