How do you know how much fabric is requirred?
 

I do not have a pattern picked out, but I want to purchase fabric for a queen size quilt. I have the fabric picked out, but I do not know how much yardage to buy. Please help me. Thank you.

Try the calculator app at Robert Kaufmann. I keep it on my iPod in my pocket whenever I shop fabric. Showed it clerk at LQS and she made note of it, as it would help them to have it handy, too.
http://www.robertkaufman.com/

It would help if we knew what size (in inches) you are planning to make this.

I figure 10 yards total as a minimum for the top. Probably more, depending on the complexity of the pattern and if you want a big queen size or a little queen size.

Fabric requirements depend on the size of the quilt (even queen size quilts vary widely in size), the design, the number of fabrics... It's very difficult to buy fabric for a specific quilt without knowing all of these.

When I know what fabrics I want to use but don't know what pattern I want to use yet I buy at least 5 yards of the focus fabric, 3 to 4 yards of the background fabric and 2 yards of at least two go with fabrics.

Scissor Queen: I like your thinking. Who needs a fancy calculator.

Makes sense to me.

I figured that out from making quilts from my own stash. I'd pull a focus, background and go withs and only have enough of one of the fabrics for a twin size. Or only have enough of the focus for the borders and not enough to add to the blocks, etc.

I have a focus fabric right now that I know I'm only going to have enough of for a fairly small quilt. The sad thing is it is *the* perfect fabric for the bed in the guest room. So now I'm going to have to punt and figure something out to still use that fabric.

Just do what i do... estimate and buy double what you might need. LOL