What a strong, healthy boy! I sort of miss having a big lub like that!
Ethan is 25 inches and probably around 13 lbs. He's about average, I think.
My DS1 Eli was MASSIVE. He was big when born, and also formula fed. By 3 months old he was over 17 lbs.
At 4 mo M was about 25 inches, and now at 4.5mo I think he's in the 17lb range but I'm really not sure. He's fitting 9mo clothing pretty perfectly, and 6mo pants. I have him in a couple 12mo onesies that don't look ridiculous, but the sleepers are too big still. He can still wear a few of the bigger 6mo stuff.