Wood Weight Calculator
Estimate the weight of a wood board or timber in pounds using its dimensions and species density. Ideal for planning lumber shipments, structural load checks, or workshop material handling.
About this calculator
The weight of a piece of wood depends on its volume and the density of the species. Volume is calculated from length, width, and thickness in inches, then converted to cubic feet by dividing by 1,728 (since 1 ft³ = 12 × 12 × 12 = 1,728 in³). Multiplying that volume by the wood's density in pounds per cubic foot gives the total weight. The formula is: Weight (lbs) = (length × width × thickness × density) / 1728. Density varies widely by species — balsa runs about 9 lbs/ft³ while hard maple can reach 45 lbs/ft³ — so selecting the correct species density is critical for an accurate result. This calculation is essential for structural planning, freight estimation, and safe workshop lifting.
How to use
Suppose you have an oak board (density ≈ 45 lbs/ft³) that is 96 inches long, 6 inches wide, and 1.5 inches thick. Plug into the formula: Weight = (96 × 6 × 1.5 × 45) / 1728. First, multiply the dimensions: 96 × 6 × 1.5 = 864 in³. Then multiply by density: 864 × 45 = 38,880. Finally, divide by 1,728: 38,880 / 1,728 ≈ 22.5 lbs. So that single oak board weighs roughly 22.5 pounds — useful to know before loading it onto a shelf or shipping it.
Frequently asked questions
How do I find the density of different wood species for the weight calculator?
Wood density values are published by organizations like the USDA Forest Products Laboratory and the Wood Database. Common values include pine at roughly 31 lbs/ft³, red oak at 44 lbs/ft³, and walnut at 38 lbs/ft³. Using air-dried (12% moisture content) density figures gives the most practical results for finished lumber. Always verify the specific species, as density can vary even within a species group.
Why does moisture content affect wood weight calculations?
Wood is hygroscopic, meaning it absorbs and releases moisture from the surrounding air. A green or freshly cut board can weigh 50–100% more than the same board kiln-dried to 6–8% moisture content. The density values used in this calculator typically assume air-dried lumber at around 12% MC. If you are weighing green lumber, you should use a higher density figure or consult a green-wood density table for an accurate result.
What is 1728 and why is it used in the wood weight formula?
1,728 is the number of cubic inches in one cubic foot (12 × 12 × 12 = 1,728). Because this calculator takes length, width, and thickness in inches, multiplying them together gives a volume in cubic inches. Wood density, however, is expressed in pounds per cubic foot. Dividing by 1,728 converts the cubic-inch volume to cubic feet so that the units are consistent when multiplying by density to get weight in pounds.