How Much Yarn?

If I’m designing my own sweater and I make a swatch and get it all the way I want it, how do I know how much yarn to buy?

This might be useful.

Here’s another estimate.

I suggest getting more than you think you’ll need especially if you’re designing your own. You don’t want to run out of a critical color or dye lot. Some places will let you return skeins if they haven’t been wound into a ball or used. Or you could just use leftovers for small projects which is what I do.