Calculate how to attach sleeves

So I have a question about how to attach sleeves to the body of a long cardigan. The sleeves have a straight cast-off of 84 stitches, and the body has 120 rows straight up and 11 bindoff stitch to the shoulder, so double that equals 284. How can I stretch 84 stitches to cover 284?

Thank you in advance for your assistance.

![Screenshot_20230512-160003_Samsung Notes|675x1200]

Here’s the other thing I wanted to attach

Assuming this cardigan is knit in pieces and then seamed, I would first seam the shoulders together. Then, lay out and pin your sleeves so the midpoint of the sleeve is across from the shoulder seam. It won’t reach all the way down the cardigan and you don’t need to stretch it – the sleeve only goes around your arm while the cardigan goes all the way down your torso. Seam the sleeves to the cardigan. Then you can do one continuous seam up the side of the cardigan and under the sleeve to close it, and repeat on the other side.


Here’s a picture to show the layout.


It might also help to know that this kind of sleeve construction is usually called a modified drop shoulder. The “modified” refers to the small straight bite taken out at the start of the armscye.

@macintosh has given a nice diagram. This video goes into more detail:

It is a wee bit more fiddly sewing this style as opposed to a plain drop shoulder, but I’m sure you will be able to do it. Please ask if you need help negotiating sewing the “bites”.


The sleeve cast off is 84sts and the body has 120rows above the underarm decrease? Is that the join that you want to make. It would be 84sts to 240rows. For mattress stitch you would be joining one sleeve stitch to every ~3 body rows.
Are the 11 bind off sts the shoulder join? That won’t factor in setting in the sleeve just in joining front to back.
The length in inches should match up (14" top of sleeve, 14" across armhole front and back). I’d think about using a backstitch to attach the sleeves rather than mattress stitch.
Is this the pattern?

Excellent advice and great diagram! I would just add that you might want to consider pinning the pieces together before you sew. I have used my macrame T- pins for this task for many years (and now you know how old I am!) that are about 2 1/2 inches long with a crosspiece at the top that prevents them from slipping. I find that pinning keeps my pieces in place and eliminates having to keep measuring to be sure that my seams are even.

Good luck finishing your project!