Worst Item ever bought
I ordered size 6-9months for my son to be worn during summers. The size is so small that it does not fit him now at 3 months. Also, the quality of cloth is much worse than what you get @ carter/baby store for the same price. They are selling cheap stuff that is sold in other countries for the same or more price than you can find here. I would NOT recommend to buy this item. I would rather pay taxes in California than buying kids clothing again from the site. Very very disappointed at Amazon. I would rate it at 0 star but it won't let me do that otherwise.

Gerber onesies sizing tip
These onesies are "true to size" IF:

1. your child is small for his/her age, AND
2. you wash in cold water and always line-dry, never machine-dry them, to prevent shrinkage.

Example: my 18mo daughter is petite in weight at just over 22lb. She is a little over 30in tall, so she's in the correct height range for 18mo according to the onesies package. The unshrunk 18mo onesies, which on the package say will fit 24-28lb, fit her like a glove both in length and width.

This particular set is VERY cute - love the prints, embroidered designs, and colors. It's been fun to be able to dress a little girl in onesies after 4 boys in a row (spanning 15 years in age). And yes, the other reviewers are right, Gerber's sizing has changed. The old-style serged-sleeve onesies were much roomier in length/width than the new ones are. The old size M (19-26 lb) onesies are BIG compared to these, and that's even after taking shrinkage into account.

Cheap!!!
i feel like gerber clothing is cheaply made i only bought them because of the color palette but i am detemined to not give gerber any more of my money.try lovable friends 9-12 mos.fits 20 lbs well

Inaccurate Sizing & Horrible Snaps (18-mo size)
I purchased the 18-month size onesies for my son when he was about 15 months old and around 24.5 lbs. He is tall but lean for his age, so I assumed he would fit nicely into these onesies that indicate they fit for babies between 24-28 lbs. I was disappointed to find that I could barely get them on him. Perhaps they fit poorly because of his height, but at the low end of the weight range, I would have thought these to have fit him nicely. I don't remember having this much of a problem with the smaller sizes that we previously had when he was younger (0-3 & 3-6), but who knows - that was when was a tired, delirious mother living my life in sleep-change-feed-change-feed cycles & probably wouldn't have noticed much outside of that rhythm.

Another irritating problem with the 18-month size is that the metal snaps began to separate from the fabric after the first post-use wash, and upon the next wash, a couple of them came off completely. We were very gentle with the snaps, but perhaps they were worn more quickly because of the poor/tight fit.

I would not recommend these, and will not buy them again (not even in a bigger size). I was too frustrated with the wasted purchase. What a shame, because the designs and colors are cute.

Great little onesies
These are really great and convenient. They seem to run small to size though - my grandson is only 4 months and weighs within the recommended size and he is almost too big for them already.