Switching yarns hence getting correct gauge for pattern

I would like to do a cat Bordhi unfelted sling bag. The pattern calls15 sts=4" w/ US10. She used Skacel Filo & Fili cotton.

I have found some colored cotton i like by elann but it is 22 sts= 4" w/ US 6. I have not bought the yarn yet for a true gauge sizing.
What I don’t understand is many fold.

  • how do i change my cast on to the correct number of stitches.
  • how do i calculate how much yarn I need?
  • will the needle size change the size or length? yes, it is a bag but the shoulder strap length is still important.
  • what else am i forgetting to take into consideration?
  • i could not find any of her yarn to see what its weight is nor knit a bit to see what the texture of the gauge is. I would think it would need to be tight but size 10 seems big for tight gauge yet how would things not poke out?

I have knitted several bowls and a cat bed that have had to be felted. those projects have been loose so I can’t imagine what a non felted bag tension(?) is like. I am making this as a thankyou gift so I really want to get it right!
Thanks for your assistance.


I am in work so can’t type out a full answer but if you click on this link to my blog there is apost a little way down the page that decribes the calculations involved with gauge.

Hope it is of some help.

If you doubled the yarn, you might get the correct gauge; sounds like the yarn is very thick. If you knit the bag in your yarn, you might want to use size 5s, double the stitches and double the yardage.