Help with raglan sleeve

Hi everyone

I am knitting a rib-knit dress for my daughter without a pattern. I have knitted the front and the back separately and I would like some help with the raglan sleeves. I have read in Knitty .com that the number of sts to cast on for the sleeve is 20% of the stitches for the chest measurement and working through the sleeve you reach 40% of the stitches for the chest measurement. Is that correct? I have 280 sts total for the chest. Does that mean that I need to cast 56 sts on for the sleeve and reach 112 sts?

Yes, that’s correct for the numbers for Elizabeth Zimmerman’s percentage system. I like to measure the ribbing at the bottom hem around my wrist to check that the sleeve cuff will fit the way I want. Then you can either increase or decrease to the given percentage of sts.

This is a nice presentation of EZ’s percentage system.