FF DS won't eat much

[Jayfer]

My DS is now 15wks old and has been on formula since wk 8. He's not a hungry baby but for his weight (13lb last week) he 'should' be taking between 30-35oz a day. He will take between 15-25oz per day.
I've tried waiting till he's shouting with hunger (then he'll take about 4oz) or cutting out a feed in the hope he'll take more at the other feeds (which doesn't happen). He's now got a cold so is struggling with congestion. He's gone to bed after only taking half an ounce and some calpol.

How long do I let this go on for before talking to HV or GP? Apart from feeding he's a happy little chap. Will it get better after weaning?

weight and appetite aren't related ime

if he seems happy, is gaining weight, wet nappies etc, then there mightn't be anything to worry about

Try a bigger teat size?

he's fine! babies are good at controlling their own appetites. he knows when he is hungry.

not all babies will eat the same amount. the tin will give an average amount for a baby of his age/weight. some will eat more, some will eat less

I honestly would not worry about this in the slightest. I presume he is gaining weight and meeting his milestones and is a happy little boy otherwise?
if so, please don't fret, and don't try and mkae him take more than he needs to

my dd was like that, up until 4 months never took the amount it said she should be according to the tin. she's always been fine. as long as he's gaining weight and having wet nappies he's getting what he needs.

my midwife told me babies will take what they want and the info on the tin is only a guide as to what the average baby takes.

Thanks for the replies.
Other than his eating he is a happy soul, very smiley and chatty. He has been gaining weight and is developing by the hour it seems so I've no worries there. His congestion is reducing the amount he will eat so my plan is to wait til he recovers from the sniffles and reassess the situation.