Circle Medallion Into Square?

Could somebody please tell me: what is the knitting formula for picking up sts. on the “corners” of a knitted circle to make it into a square? Is it 1/8th of the sts. for each corner? Or what? I read it once lonnnng ago, somewhere, but don’t remember where or what the exact answer was. I am talking about adding on 4 separate small triangles (“cat ears” if you will); I know the decrease ratio, I just don’t know the percentage of sts. to pick up.



At the corners of a square, I usually pick up 3 sts into the one corner stitch but for picking up sts on a circle, picking up 3sts for every 4 should work. (Usually for stockinette st the ratio is 3/4 and for garter, 2/3 when you pick up on a straight edge.) The alternative on the circle is one for one.
You may have to give it a try on one test corner or swatch to make sure it lies flat without pulling and that you can do the decreases nicely after the pick up.

You can turn a circle a square by doing double increases at the 4 ‘corners’. that way you increase 8 sts every other round. I’m not sure the ratio of picking up 3 sts for every 4 will work, it may pucker up the center medallion. The shaping is done with the increases, not how you pick up stitches.