4' for children works and 4-5" wide so it wraps easily
5.5-6Ft for adults as they really need to wrap the neck and be able to tie.
If working a K2P2 rib it will pull in and not provide the neck coverage needed for really cold weather. I think a wider rib (K3P1) or a broken rib works better if rib knitting is what you want to do. Basket weave is a good simple pattern that works for men, too. And if using worsted wt yarn, would use a larger needle to ensure the fabric has good drape.
5.5-6Ft for adults as they really need to wrap the neck and be able to tie.
If working a K2P2 rib it will pull in and not provide the neck coverage needed for really cold weather. I think a wider rib (K3P1) or a broken rib works better if rib knitting is what you want to do. Basket weave is a good simple pattern that works for men, too. And if using worsted wt yarn, would use a larger needle to ensure the fabric has good drape.