Buying new awning fabric....Need HELP!!!

I am buying replacement awning fabric for my 2004 Gulfstream Ameri Lite 21mb can anyone out there tell me what size the awning should be. Every time I think I have found one it ends up being the wrong size. Is the fabric supposed to be 14 or 15 ft or is that the measurement from arm to arm? The fabric that is on there now looks too small.

[johno02]

Where are you planning on buying from?? If a web site, they should have instructions on how to measure. If not, look somewhere else.