you don't cast on to crochet. you do a base chain. to answer this question, you need to take into account the size thread you are using and the size hook. why don't you do crochet a diagonal stitch afghan. when it gets to be 60" wide, you decrease. there is a book delma's diagonal stitch which you can get, or search for a free diagonal stitch pattern. good luck
The cast of Afghan - 2008 includes: Pardis Parker as Husayn
The cast of Afghan Memento - 2010 includes: Matthieu Beguelin
The cast of Afghan Abla - 1934 includes: Sultana Kamala
The cast of Crochet au coeur - 2005 includes: Roger Muni Alain Simon
The cast of The Mystery of the Afghan Gold - 2005 includes: Christopher Nissley as Narrator Levon Sharafyan as Afghan Aleksandr Sountsov as Alexander The Great
The cast of Afghan Girls Can Kick - 2008 includes: Homa Saboor as Social worker
The cast of Afghan Muscles - 2006 includes: Noorrulhoda Shirbad as Noor Hamid Shirzai as Hamid
The cast of An Afghan Night - 2008 includes: Ran Levi as Ran Haim Zanati as Haim
The cast of Arus-e afghan - 2004 includes: Golab Adineh Hosein Yari
The cast of Crochet Noir - 2013 includes: Chess Julia Allan as Grace Ant Neate as Joe Kevin Powe as Tony
The cast of Sher E Afghan - 1966 includes: Nishi Prithviraj Kapoor Prem Nath Zeb Rehman
The cast of Paaizeb - 2010 includes: Setareh Ahi as Afghan Woman Yaseen Mirzai as Taliban Warlord Firieba Sarwarzadah as Afghan Girl