Waist - Measured at the natural waistline. For velcro or snap covers and diapers the smallest setting is with the fasteners closed and the elastic (if applicable) fully relaxed. The largest size is with the fasteners at the largest setting and the elastic lightly pulled. For pull up style covers, the smallest measurement is taken with the elastic fully relaxed. The largest setting is with the elastic pulled about 95%. You should not measure over a diaper.

Leg - Taken diagonally at about where the leg opening on the cover or diaper would be (see picture). For velcro or snap covers and diapers the smallest setting is with the fasteners closed and the elastic on the leg fully relaxed. The largest size is with the fasteners at the largest setting and the elastic on the leg lightly pulled. For pull up style covers, the smallest measurement is taken with the elastic fully relaxed. The largest setting is with the elastic pulled about 95%. You should not measure over a diaper.

Rise - The rise of the cover is measured by taking the cover and laying it out flat. From the top of the front of the cover or diaper to the top of the back of the cover or diaper is the rise. To measure this on your child, measure from the front waist through their legs and back up to their waistline in the back.  A larger number in the rise will mean that the diaper or covers will mean a higher waistline. 

Covers: For the rise measure over the diapers that you want to use. 

When trying to decide upon a cover size, start with the suggested weights and then see if the waist, leg and rise measurements of your baby fall into the range of that cover. If you start with the measurements you may end up with a cover that is way too big. But, you do know your baby best. Most covers have suggestions on the page as to how they fit. For all the velcro covers, you are looking for waist and leg measurements that fall in about the same place in the range.  If your baby’s waist measurement is on the lower end of the range and the leg measurement is on the higher end of the range, the cover will probably be too tight at the legs. An exception to that seems to be the Bummi Super. The leg gussets are not sewn like the other covers and seem to be more forgiving. Since the Bummi pant doesn’t use fasteners the waist and leg measurements can fall just about anywhere on the range.

The Fuzzi Bunz covers fasten with snaps that can be fastened independently of one another. You probably won’t be able to use the smallest leg setting with the largest leg setting. Fuzzi Bunz are made to be used with an newborn 4x8x4 prefold diaper or the 4x6x4 regular prefold diaper. If you are using the Fuzzi Bunz with a 4x8x4 (the premium size) diapers and your baby is near the top of a size range, you may want to get the next size up.

When trying to decide upon a diaper size, start with the suggested weights and then see if the waist, leg and rise measurements of your baby fall into the range of that diaper. If you start with the measurements you may end up with a diaper that is way too big. But, you do know your baby best.  For all the all in ones and fitted diapers, you are looking for waist and leg measurements that fall in about the same place in the range.  If your baby’s waist measurement is on the lower end of the range and the leg measurement is on the higher end of the range, the diaper will probably be too tight at the legs.