How many yards of yarn do I have to spin to make that?
Your pattern tells you you need so many ounces of a certain type of yarn, or worse still, doesn't tell you how much yarn you need. How much should you spin?
I've made this handy calculator which will work it out for you. It's still very new, and the calculations are based on my own notes and my own tension, so please only use it as a rough guide. If you find it right, close or way off, I'd really appreciate your help to fine-tune this calculator. Email firstname.lastname@example.org.