I this question quite a bit so I thought I would discuss it in my blog as well as the FAQ page of the Firewood Manitoba website.
The following website from Measures Canada discusses it in great detail:
http://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/lm03963.html
In summary a cord of firewood is 128 cubic feet of stacked firewood and air. Traditionally this is a stack 4 feet wide by 4 feet high by 8 feet long, though it doesn’t matter as long as the stack of firewood eqals 128 cubic feet.
At Firewood Manitoba it is not feasible to stack the cord before delivery so the firewood delivered is actually taking up 180 cubic feet of space. This is becuse the firewood is loose in the load instead of stacked so it takes up more space. In the past we have stacked the 180 cubic feet of loose firewood several times to test if it equals 128 cubic feet stacked and every time we get slightly over 128 cubic feet of stacked firewood.
This ensures that when you order a cord of firewood from us (or fractions of a cord) you actually receive a cord of firewood which is a stacked pile of firewood which equals 128 cubic feet.
Thanks for your time.