How do you measure for a raglan sweater sleeve length?

I need some guidance, please. I am working on this top-down raglan-sleeved sweater for my great-nephew (age 2) and I am stumped about how long to make the sleeves. He lives several states away so I can’t try it on him. His mother measured him for me and gave me a measurement of 12" from neck to wrist but I keep thinking that will make orangutan-length sleeves. So to get the right length, do I take the measurement on the sweater starting from where the raglan seam starts at the collar and go 12" from there?

Alternatively, the pattern says “Continue knitting in stockinette stitch until the sleeve measures 5 (5.5, 6.5, 7, [B]7.5[/B], 8) inches or 1” less than your preferred length.” If I go with the pattern-recommended length (7.5" in his size), do I start measuring for the 7.5" from where I picked up stitches to continue the sleeves or from the top (neckline) of the raglan seam or from the bottom (armpit) of the raglan seam? :?? Why yes, I [I]am [/I]completely inexperienced at making sweaters. :hair:

Arm length is measured from the underarm to wrist, to avoid the complication of the different types of shoulder styles.