These do actually hold pee more than I expected. My daughter has hard time potty training (she's 3 in one month), so we thought these would be a good in between trainer. Pull-ups are just like diapers so they don't help her any. these however she doesn't like to pee in. only reason I knocked off a star is bc they don't always hold the pee so well and I have carpet throughout most of  my house so a little unnerving. I'm sure there are covers I can get for them or liners or something. anyway they fit well -she's in a 3T, sometimes 4T (weighs about 35lbs) and we got size 3T. There's even some room to grow. They aren't snug anywhere, but fit just right. overall good purchase.