Lumber Weight Calculator
Work out what a board weighs from its size, species and moisture content — using the actual dressed dimensions, not the nominal ones.
Lumber Dimensions
Picking a size fills in its actual dimensions below. Edit those directly for rough-sawn or non-standard stock.
Wood
Moisture is the biggest swing in lumber weight. A moisture meter reading can be entered directly with the custom option.
Weight
9.3 lb
4.2 kg per piece
Volume per piece:0.292 ft³
Density at 8% MC:31.8 lb/ft³
Actual dimensions:1.5″ × 3.5″ × 8′
Densities are typical published values at 12% moisture content, rebased to the moisture content you select. Individual boards vary with growth rate, grain and how long they have been drying, so treat the result as a close estimate rather than a certified figure.
Frequently Asked Questions
- How do you calculate the weight of a piece of lumber?
- Multiply the volume of the board by the density of the wood. Work out volume from the actual dimensions in inches, divide by 1728 to get cubic feet, then multiply by the density of that species in pounds per cubic foot. A kiln-dried Douglas fir 2x4 at eight feet long works out to roughly 9 pounds.
- Why is a 2x4 not actually 2 inches by 4 inches?
- Lumber is named by its rough-sawn size but sold after it has been dried and planed smooth, which removes material. A 2x4 actually measures 1.5 by 3.5 inches. Nominal widths under 8 inches lose half an inch and those 8 inches and over lose three quarters of an inch, so a 2x8 measures 1.5 by 7.25 inches.
- Does using nominal instead of actual dimensions matter?
- Yes, and it is the most common mistake. Calculating a 2x4 as 2 by 4 inches instead of 1.5 by 3.5 overstates its volume, and therefore its weight, by about 50 percent. The exact error varies with size: a 2x10 comes out roughly 44 percent heavy. This calculator always uses the actual dimensions.
- How much does moisture content change lumber weight?
- A great deal. Green lumber straight from the mill can weigh 40 to 50 percent more than the same board kiln-dried, because it is still carrying water. Pressure-treated lumber is usually sold wet and is heavier again. Choose the condition that matches your stock rather than assuming dry weight.
- Which wood species is heaviest?
- Among common building timbers, dense tropical hardwoods such as ipe are the heaviest at around 69 pounds per cubic foot, followed by hickory and white oak. Western red cedar and eastern white pine are among the lightest at roughly 23 to 25 pounds per cubic foot, which is why cedar is popular where weight matters.
- Can I use this for rough-sawn or milled lumber?
- Yes. Choose Custom, or simply type the measured thickness and width into the dimension fields. The nominal size dropdown will switch to Custom automatically when the dimensions no longer match a standard size.