Lumber Weight Calculator

How to find lumber weight from board feet

A lumber weight calculator turns a board-foot count into pounds. Enter the number of board feet and the wood density in pounds per cubic foot. The tool multiplies board feet by one twelfth and then by the density.

A board foot is a chunk of wood 12 inches by 12 inches by 1 inch. Twelve of those stacked make one cubic foot. So a cubic foot of wood is 12 board feet, and the weight of one board foot is the density divided by 12.

The formula in plain words

1. Cubic feet = board feet ÷ 12.
2. Weight in pounds = cubic feet × density in lb per cubic foot.

The page opens with a density of 35 lb/ft³, a round figure for softwood framing lumber. You can type any number that matches your species.

Worked example: a pickup load of framing

You are hauling 100 board feet of softwood at 35 lb/ft³.

• Cubic feet: 100 ÷ 12 = 8.333
• Weight: 8.333 × 35 = 291.67 lb

Worked example: a stack of hardwood

A pallet holds 500 board feet of a dense hardwood, taken at 45 lb/ft³.

• Cubic feet: 500 ÷ 12 = 41.667
• Weight: 41.667 × 45 = 1,875 lb

That is almost a ton on a pallet, which is worth knowing before you lift it with a small trailer or a hand truck.

Weight of 100 board feet at different densities

Density	Example wood type	Weight of 100 bf
23 lb/ft³	Light softwood such as cedar	191.67 lb
27 lb/ft³	Light softwood	225.00 lb
35 lb/ft³	Typical framing softwood	291.67 lb
45 lb/ft³	Medium hardwood	375.00 lb
47 lb/ft³	Dense hardwood such as white oak	391.67 lb

The densities in this table are rough, air-dried values. A species chart from a lumber supplier or forestry source will be more exact. Water adds a lot of weight, so freshly cut or pressure-treated lumber can be well above the dry numbers.

Nominal size versus real wood

Here is the catch. Board feet for dimensional lumber are counted from the nominal size. A 2x4 that is 8 ft long counts as 5.33 board feet. At 35 lb/ft³, the calculator gives 15.56 lb for that board.

The actual stick is 1.5 in by 3.5 in by 96 in. That holds about 0.29 cubic feet, so it weighs close to 10.2 lb at the same density. The calculator reads about 50 percent high for finished framing lumber because nominal volume is bigger than real volume.

For rough-sawn lumber that really is a full inch thick, the formula is accurate.

How to get your board-foot count

Board feet = thickness in inches × width in inches × length in feet ÷ 12. Do that for each board size and add the results. If you buy by the board foot, your supplier’s invoice already lists the total.

When the weight matters

Knowing the pounds helps with practical decisions. A half-ton pickup has a payload rating printed on the door jamb, and a 1,875 lb stack of hardwood eats most of it. Stairs, hand trucks, and a second pair of arms are easier to plan when you know a bundle weighs 300 lb and not 30.

It also helps with shipping quotes. Freight carriers price by weight and class, so an estimate beats guessing when you fill out a form.

Common mistakes

• Using the density of dry wood for treated or green lumber. Moisture can add a large share of the weight.
• Applying the nominal board-foot count to finished lumber and treating it as exact. See the 2x4 note above.
• Forgetting packaging. Straps, pallets, and wrap add a bit to a shipped bundle.
• Treating this as a structural load check. For deck framing, dead load is one input, and framing must be checked against the code or by an engineer.

Related calculators

To see what a whole deck must carry, use the deck load calculator. The beam load calculator turns a span and load into moment and reactions, and the I-beam weight calculator does the same job for steel shapes.