Wood weight calculator
Pick a species, give the size of the boards (or the board feet) and how dry they are. The weight comes from the USDA Wood Handbook's specific gravity for that species, worked to your moisture content with the Handbook's own equations.
Units
Weight
14.7 lb
6.7 kg · 44.1 lb/ft³ at 12% MC
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Red oak's density at 12% moisture, worked from the Handbook's specific gravity, times your volume.
Why these numbers?
The situation
The Wood Handbook gives northern red oak a specific gravity of 0.63 at 12% moisture content and 0.56 on the green volume (oven-dry weight over volume).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
What that means
You set the moisture content to 12%.
From your input: moisture content
So
At 12% the Handbook's own specific gravity applies directly: density = water (62.43 lb/ft³) × specific gravity × 1.12 (Eq. 4-14).
Arithmetic: exact by definition , sources [1]
The number
0.333 ft³ × 44.05 lb/ft³ = 14.68 lb.
Arithmetic: exact by definition
Sources
Hardness, movement and uses: Red oak wood.
How the weight is worked out
Specific gravity is the weight of the dry wood alone compared with the same volume of water. The Handbook prints it for each species at 12% moisture content and on the green (freshly cut) volume. Density at your moisture content is the water's density, 62.43 lb/ft³, times the specific gravity at that moisture, times one plus the moisture as a fraction (Handbook Eq. 4-14). Away from 12%, the specific gravity is moved with the species' volumetric shrinkage (Eqs. 4-9 to 4-11); where the Handbook prints no shrinkage it gives its own estimate (Eq. 4-13), and the result says so.
Volume is thickness × width × length for each board, times the number of boards, or your board feet divided by 12 (a board foot is 144 cubic inches). Use the actual size, not the nominal one. "Green" uses the Handbook's average moisture content for freshly cut heartwood of that species (Table 4-1), or sapwood where no heartwood figure is printed.
What it can't tell you
Two boards of one species can differ: for common US species the Handbook gives a coefficient of variation of about 10% for oven-dry density (p. 4-11). Treat the answer as a planning figure, and weigh a sample board when the number matters.