Hat knit in the round -- how many decreases?

Hi,
I’m trying to figure out how to adjust a pattern for a hat knit in the round, specifically, how do you figure out how many decreases are needed to close up the cap.

In most patterns, I read something like:
row 1: k5 k2tog across row
row 2 and all even rows: knit across row
row 3: k4 k2tog across row
row 5: k3 k2tog across row
row 7: k2 k2tog across row
row 9: k1 k2tog across row
row 11: k2tog across row
Cut yarn, and pass yarn through stitches, pull tight to close cap.

This is basically the pattern I want to follow, except this pattern is for a hat knit over 80 stitches. How would I adjust it for a hat knit on 40 stitches? Would I just start with k3 k2tog and hope it works? Is there some magic formula? I’ve consulted all my books, but have not found the answer.

Oh Knitting Sages, please help!
Thanks!

i always make sure i have a multiple of 10 when i start decreasing unless i am working on a specific pattern. then i take two off that multiple and go from there. (yeah i know that didn’t make sense)

so yes i would do was you suggested…knit 3, k2tog. the in would knit a round even. the next round i would knit 2, k2tog…

when it is multiples of 10 it works perfect because you can just step down like that until you are doing k2tog all the way around…

Thanks! :cheering: :cheering: