should I be uping his formula intake?

I think thats just great he seems like a healthy kid :) My son is 4 months old and he was born november 19th and i make him 8 ounce bottles but he usually drinks like 6 and saves the rest for a little later. I give him 3 ounces of formula mixed with baby rice single grain cereal around noon and then he eats anything from sweet potatos, green beans, he loves bananas, carrots to and pears and chicken and rice baby food he gets one jar of any of those around 5 or 6 pm for his dinner and wants a bottle after words which he eats the whole jar! My baby is only 16 pounds and 24 inches hes a short stalky lil guy getting some cute lil chunk roles but i wouldn't worry about upping your babys formula intake just whatever he wants, if he's a binky baby sometimes they just wanna suck suck suck suck so if he finishes an 8 oz bottle and acts still hungry he might just want to suck give him his binky after you burp him thats what i do :)

at 28 inches and 18 pounds he is tall, which means he's growing great so keep doing what your doing and what you think he needs. (my daughter was 29 inches and 20 pounds at 12 months lol I can't believe your son is already 28 inches, as soon as he walks sign him up for basketball!)