Dear Knitting kids:
I need formulas for two problems:

I would like to know how to take a pattern for a pull over and make it into a cardigan? Surely there is a mathematical process for doing this!

It’s about those dang armholes!! Is there a scale someplease, or a graph that tells you what the height/width of an armhole should be for a certain size baby/child/manchild, etc.? Why can’t I just knit until it looks good enough to get into comfortably? Why does every baby project turn out with armholes too small? I know my gauge is spot on, so what is the dang problem–can’t we just agree that a size 6, or 8, or . . . . will have an armhole that is this long by this wide?
Happy New Year to all!