Estimating yarn yardage

[Sahara]

How does one estimate the amount of yarn needed to complete a project?

[knitqueen]

This calculator will help, but it can only be used accurately for figuring out yardage for a rectangle, and only a few different stitch patterns. I don't know if it will help, it entirely depends what type of project you are planning, but it might give you a very rough idea.

[janelanespaintbrush]

It would help if we knew what you were making. Here's a guide for some basic projects in different sizes and gauges. This works for sweaters. Here's one more sweater guide that's handy when you're out shopping. I know that there's also a handy guide you can buy, though I've never seen it in person so I don't know whether it covers stuff the others don't.

[Sahara]

Thanks, all, for your advice.
I've been busy since my querry. I found the calculators y'all mentioned. Now all this mathaphobic brain has to do is try to follow the directions.
I am trying to figure out if I have enough yarn for a simple T shirt style sweater with 3/4 length sleeves and a wider, round neck. I don't want to start it and discover I don't have enough. I hand dyed the wool last summer with plans to start on it in the fall. Well . . . that didn't happen. Now, I'm not sure.