The Long Tail Cast On was the first way I learned how to cast on in knitting, and it is a great method for a lot of applications.
But it had one major problem to me:
estimating how *long* a tail to begin with.
Oh, I'd heard of wrapping the yarn around the needle and other ways to try to figure it out, but when I needed to cast on 240 stitches the other day for a cowl, I assumed I could just use my knitted cast on instead. It doesn't begin with a long tail, so no worries about it being too short.
But the knitted cast on didn't give me that nice edge that the long tail cast on does, so I decided it was time to search the internet for an answer.
Lo and behold, I found it on this blog: Taking Time to Smell the Roses, at Jackie-es.com. Her entry, The Mathematics of Long Tail Cast On, was exactly what I needed.
So, if you ever need to know, and Mr. Google hasn't directed you to Jackie's post, here is the formula in a nutshell:
[ (Number of stitches) X (mm needle size) / 8 ] + some extra for weaving in later.
This gives you the number of inches of yarn you need for your tail.
I do suggest you pop over to the original blog post and enjoy the entire entry:
Thank heavens, once again, for the power of the internet and sharing, generous people like Jackie. ♥