Here's an answer . . but you will have to apply some math & logic.

You didn't say what thickness, so perhaps you are looking for a 'Universal
Constant'. Because it is inherently a natural product, I don't believe there
is one. However here is something that can be used in the same vein.

A 4x8 sheet of 1/4 inch ply weighs 'about' 25 pounds. This seems to be a
fairly constant 'multiplier' - i.e. a 1/2 in thick sheet weighs about 50
pounds, and a 3/4 inch about 75 pounds.

Do some simple calculations and you get the weight per square foot, or even
down to per square INCH, if you need it.

Regards & Good Luck,
Ron Magen
Backyard Boatshop
{PS - There ARE tables that give the density of different woods {by
species}. This could be used to approximate the additional mass of your
scantlings}
"mscres" wrote in message
...
Anyone can give a quick answer to Plywood Density? Or just average weight
per square foot of .5 in Plywood.
It seems my calculation to by boat weight is wrong.

Thanks in advance