The number refers to the square footage of the canopy. These days with tapered/semi-tapered canopys it is rough to relate them exactly to a length * width type of thing.
You use the square footage of the canopy to determine wingloading (LBS / Sq Ft) of the canopy. There are also other things that you can infer from the canopy size. Generally speaking for a particular model of canopy, the smaller the faster, and more responsive. This comes from shorther lines, and higher WL.
(This post was edited by Fast on Sep 4, 2003, 10:56 PM)