Baby knits - sizes & dimensions

I have a number of baby knit patterns, some of them very old and in d/c ed yarns. How do I figure out which size is for what size baby. Like a cap for a newborn - what circumference if knitted in baby, in sport and in worsted? The same for a 3-month, a 6-month, etc. Are there sizing charts available somewhere? And for booties, what is the length of the finished soles for the various sizes? I have a booklet (currently in the stores) called “winter warmers.” It has a pink snowflake hat and booties but is made from Red Heart Super Saver which is a worsted. I wanted to make it from a DK or sport or even baby weight. How do I do the conversions for the 2 sizes, newborn and 6 mos?

If there’s a gauge given, figure how many inches the sts per inch work out to, then covert to your gauge in the smaller yarn. So if the CO is 60 sts at 4sts/inch that = 15 inches.

But how big around should I make a cap for the various sizes/ages and how long should the sole of a bootee be for the various sizes? I’m looking at going mainly from a worsted down to a finer yarn.

Ohhh, I see. Here’s a couple charts, but they’re only for sweaters - and I know there’s one for hats somewhere, I’m sure someone will come up with it.

Thanks for those links. The first actually did have a head circumference chart and some other charts that will be useful. Guess I’m going to have to experiment with yarns and needle sizes to figure out how to convert from the worsted to the baby yarn.