The general mathematical rule is 150mL per kg per day - then just divide that amount up in to how many feeds she has per day... We found Sam was pretty much always below what was recommended on the formula tin, but always pretty much right by the way the hospital calculated it.

Personally, I think it's formula companies trying to get you to waste formula so they sell more...

When it comes to teats, which ones are you using? Signs that she needs a faster or different teat will be if she's collapsing the teat while she sucks. With the standard hospital teats, Sam would do this all the time and the poor little boy would suck and suck and suck and get nothing because it was collapsed... He just needed a different one then. When he needed a faster one, we'd often hear a kind of clicking sound, and you'd see a great gush of bubbles going back into the bottle when he released it. We use avent teats and find that Sam also runs below the recommended ages on the teats - we don't change him because he's hit the magic age, we change him when he shows signs of needing a faster teat.

BW