@Kara I am breast feeding, so it is not possible to know exactly how much he gets. I am taking extra time for feedings, making sure that he eats as much as he wants/can. This morning I fed him a bottle of expressed mm and he ate 190 cc, which is what he would need for 4 hour easy.
General update
DS has been a bit whiny the past 10 days. Also there have been night wakings for a week, where he normally sttn. He has a cold that is bothering him. Also as mentioned in replies a gs and a developmental leap. I noticed that he could handle longer a-times. At first I wanted to wait until he felt better, but then I felt he needed the change. I transitioned to 4 hour easy in steps. A bit faster than I have seen advised on de forum. No 5 minute increases, he could handle more. but I do look closely to see if he can handle what we are doing. Actually the morning has been 4 hours mostly for quite some time now. Then I changed the afternoon to 4 and kept that for a few days. Since two days we are on a full 4 hour easy and so far so good. Yesterday he had longer naps and for two nights now he has sttn. Hope this continues!