- Loosely wrap the yarn around your needles 10 times. Pinch and hold where the 10th stitch ends and pull the wraps off the needle. You then multiply that length by the number of stitches needed to cast on. (I also like to add a couple of extra inches just to be safe)
- Multiply the width of the final project by 3 then add 6 inches for the tail. This should give you the correct amount of yarn needed to cast on your project. For example: If you are working on a project that will measure 10" wide when finished multiply 10x3+6= 36 inches
- Wynnknit.com has posted a great document that gives estimations on the length of tail needed based on yarn weight and needle size.
New to long tail cast on? Here are a couple of great videos to help you get started:
Knit Picks: Long Tail Cast On
New Stitch A Day : Long Tail Cast On