(approximate) sizes for baby stuff?

[isabeau]

I have a lot of friends that are, er, acquiring babies, and I want to do up baby hats and baby booties. I found a pattern that I like for baby booties (link) but it doesn't give gauge, and I'm using slightly larger needles and a different size yarn so it's coming out way too big.

Problem is, I don't have any babies of my own to measure, and so I don't know how much to compensate. (And I have a similar problem with hats; some patterns say "will fit newborns" but I don't know how to adjust for a several-month-old or whatever.)

So is there some sort of guideline for baby clothing sizes (eg average circumference of ankle, length of foot, size of head both for width and height)?

[globaltraveler]

Ah. I've just been here.

Try here. And also here.