What's the difference between a sized diaper and a One-size diaper? (scroll down for fold over vs. snap down rise)
The main difference is sized diapers are made to fit a specific weight range. Typically these diapers come in newborn or XS, small, medium, large, and extra large. Since they are made for a smaller weight range, they are less bulky and sometimes easier to get a good fit on a baby. They have nothing to adjust the height of the diaper, it is the size it is, if that makes sense.
One-size (OS) diapers are made to fit a large weight range, usually 10-35 pounds. These diapers are bulkier on a smaller baby, and fit more trim as baby gets older and bigger. They do not generally fit a newborn well. Sized XS or Newborn diapers are best for tiny babies. Even though a lot of OS diapers state they'll fit around 8lbs, most people find they fit best once baby bulks up a bit around 10 pounds. OS diapers feature either a snap down rise or a fold over rise. A snap down rise features a couple rows of snaps on the front of the diaper, you can snap these to eachother to customize the rise/height of the diaper. A foldover rise has one row of snaps on the outside of the diaper, and another row on the inside. You fold the inside row down and facing out of the diaper, and it makes the rise/height of the diaper shorter.
Left is a size Small Bumgenius. Right is a OS BumGenius
The snaps on a OS Bumgenius
The small next to the OS snapped down to the smallest setting.
The difference in bulkiness in the small and the OS on the smallest setting.
Here is the small on Claire at about 13 pounds.
Here is the OS on Claire on the smallest setting.
Here is the OS on the medium setting.
And here is the OS all the way unsnapped to make it a Large. You can see how big it is right now!
This is a different brand of OS diaper - a Rumparoo. This has 4 size settings. This is on XS (it's a little too short for us now) The Rumparoo is one of the few diapers that really does fit a smaller baby (under 10lbs) - but it doesn't quite last as long because it's smaller than other OS diapers.
This is the small setting, fits perfect now.
The medium setting.
The largest setting. Still lots of growing room, but not as much as the BumGenius.
One-size (OS) diapers are made to fit a large weight range, usually 10-35 pounds. These diapers are bulkier on a smaller baby, and fit more trim as baby gets older and bigger. They do not generally fit a newborn well. Sized XS or Newborn diapers are best for tiny babies. Even though a lot of OS diapers state they'll fit around 8lbs, most people find they fit best once baby bulks up a bit around 10 pounds. OS diapers feature either a snap down rise or a fold over rise. A snap down rise features a couple rows of snaps on the front of the diaper, you can snap these to eachother to customize the rise/height of the diaper. A foldover rise has one row of snaps on the outside of the diaper, and another row on the inside. You fold the inside row down and facing out of the diaper, and it makes the rise/height of the diaper shorter.
Left is a size Small Bumgenius. Right is a OS BumGenius
The snaps on a OS Bumgenius
The small next to the OS snapped down to the smallest setting.
The difference in bulkiness in the small and the OS on the smallest setting.
Here is the small on Claire at about 13 pounds.
Here is the OS on Claire on the smallest setting.
Here is the OS on the medium setting.
And here is the OS all the way unsnapped to make it a Large. You can see how big it is right now!
This is a different brand of OS diaper - a Rumparoo. This has 4 size settings. This is on XS (it's a little too short for us now) The Rumparoo is one of the few diapers that really does fit a smaller baby (under 10lbs) - but it doesn't quite last as long because it's smaller than other OS diapers.
This is the small setting, fits perfect now.
The medium setting.
The largest setting. Still lots of growing room, but not as much as the BumGenius.Snap down vs. Fold Over - what's the difference?
On one size diapers there are two options to make them smaller or larger. Most big-box brand diapers feature a snap down rise. This usually consists of 2-3 columns of 3 snaps. Snapped all the way down makes them small, snapped to the middle set is medium, and unsnapped is large. Here are some pictures:
The top row of snaps will snap down to either of the bottom two rows to shorten the diaper.
Smallest setting (snapped all the way down)
Medium setting (snapped to the middle row)
Large setting (all the way unsnapped)
Here is the fold down rise: There are two sets of snaps. The outside snaps are for the largest setting. Just snap your diaper and go. If this makes the diaper too high up on baby, you fold the front panel down and out, exposing the inner row of snaps. This is called the "fold down rise" - pictures below!
You can see the outside snaps and the back of the inside snaps.
Here is the inside of the same diaper.
This is the diaper with the highest rise (so snapped to the outside snaps)
This is what it looks like with the rise folded down.
The top row of snaps will snap down to either of the bottom two rows to shorten the diaper.
Smallest setting (snapped all the way down)
Medium setting (snapped to the middle row)
Large setting (all the way unsnapped)
You can see the outside snaps and the back of the inside snaps.
Here is the inside of the same diaper.
This is the diaper with the highest rise (so snapped to the outside snaps)
This is what it looks like with the rise folded down.