I need help. I am knitting a hat for FH, it is basically Silver’s Palindrome hat without the cables (only k2,p2 ribbing). I am going to make it the same length so it will fold over. However, here is where I need help.

He wasn’t a brim, but not a regular brim, an all the way around the hat brim…he’s weird. Anywhoo, when I finish with the hat, I will fold it up and pick up 120 k2,p2 stitches. I need to figure out how to keep the k2,p2 pattern (if possible) and increase it out about 2-21/2 inches, then decrease it to match the increases. That way I can insert the brim, and fold it over and sew it up. Any ideas? I can’t figure this out.

I can follow a pattern with the best, and make some little changes to a pattern, but for this…the math and dimentions escape me.