I know the answer to my question involves math and there it ends. I have a pattern which requires 80 stitches on a 6.5 mm needle. The yarn I am using suggests 4 mm needle. How many stitches do I need to cast on to get the same result. Thanks in advance.
Hi and welcome!
It depends on your tension, how tightly or loosely you knit. Have you made a gauge or tension swatch with your yarn and needles? Then you can see if you get the pattern gauge with your yarn and needles.
What is the name of the pattern you’re following?