Hi, my first time posting here. I’m preparing to knit a sweater that has a drop-down sleeve. My question is, how do I measure for the arm length? Thank you.
Hi. I’m not sure what you mean by drop-down sleeve. Can you link to your pattern or an image of it or give us its name and where you got it? I’m thinking you mean a drop shoulder but I’m not certain. When we ask for more info it’s to be able to help you better. 
To GrumpyGramma,
Here is a link that will show the kind of sleeve/shoulder I’m asking about. Actuallly, the pattern I’ll use is Sirdar#5768, but I don’t have a pic to link to.
http://us.deramores.com/boy-s-sweaters-in-sirdar-hayfield-bonus-aran-tweed-2353
Thank you
Hi and welcome!
For drop sleeves, I knit the front and back and seam them together at the shoulders. Then I knit the collar which usually pulls in the opening left for the neck. Finally, I try it on so that I can see where the end of the shoulder will fall. I can then measure from that point to the wrist and get a better idea of the sleeve length.
Salmonmac,
Thank you. Yes, I see where your suggestion will work. Great!