How do i know when to increase the amount of formula im feeding my LO?

Hes currently 3 weeks and has 3 oz's every feed, he normally goes 3 hours between feeds, longer if hes having a good sleep, but since yesterday through the night and today hes feeding every 2 hours. is this because hes getting hungry sooner? should i add an extra ounce to his feed to satisfy him longer?

I was advised to add an extra ounce if they continually drain their bottles and feed more often than 3-4 hours! So yes, I would increase by an oz and see what happens! Sounds like he could still be a bit hungry if he is feeding every 2 hours! He could also be having a growth spurt which is making him need more calories, but his stomach can't cope with more so he feeds more often :)

hey hun, they can feed more often and have more ounces if they are having a growth spurt...Grace has around 4 - 5 every 3 hours but early in the week had a day of 6oz!! so i started making her bottles to 6 but the next day she went back to normal!
just try making a few larger bottles - Theo should stop when he's full!! xxx

Thanks ladies! Theos still sticking around the 3 oz mark a the minute, he had a little over earlier but was too sleepy with a full belly and started to drop off! Im convinced its a growth spurt now and will offer him 4oz for a day or two, doesnt matter if hes not finishing them! x

Ella has anywhere between 4 and 6oz's and she is 10 1/2 weeks old! I never know how much she will want from one moment to the next lol :) Most often it is 5oz's though!