Lumber Weight Calculator
Calculate the weight of a lumber order from nominal size, length, count, species and moisture, using dressed dimensions and a truck payload check.
By CalcBuilt Editorial TeamUpdated September 9, 2026Formulas checked against manufacturer specs, see how we calculate.
Results
- Total weight
- 578 lb
- 30 pieces of 2x6 at 12 ft, spruce-pine-fir (spf), kiln dried
- Each piece
- 19.3 lb
- 1.6 lb per 1 ft of length. The stamp reads KD or S-DRY. This is what a lumberyard sells for framing
- Board feet
- 360 bd ft
- Nominal measure for pricing: thickness x width x length in feet, divided by 12. 20.6 cu ft of actual wood
- Density used
- 28 lb per cu ft
- Spruce-pine-fir (SPF) at 28 lb per cu ft kiln dried, x 1 for kiln dried
- Trips at this payload
- 1 trip
- Against 1,500 lb of payload. Passengers, tools and a toolbox come out of that number first
Lumber Weight formula
Cubic feet each = Dressed thickness (in) x Dressed width (in) x Length (in) / 1,728
Weight each (lb) = Cubic feet x Density (lb per cu ft) x Moisture factor
Total = Weight each x Pieces
Board feet = Nominal thickness x Nominal width x Length (ft) / 12Worked example
Forty 16 ft pressure treated 2x8 joists in southern yellow pine, bought the day they came off the treating cylinder. The dressed section is 1.5 by 7.25 in, so each board holds 1.208 cubic feet.
Southern yellow pine is 36 lb per cubic foot dry, and freshly treated lumber runs about 30 percent heavier, so 46.8 lb per cubic foot. Each joist is 56.6 lb and the load is 2,262 lb. That is over the payload of most half ton pickups, so it is two trips or a delivery.
Quick reference
| Size | 8 ft | 12 ft | 16 ft |
|---|---|---|---|
| 2x4 | 8.2 lb | 12.3 lb | 16.3 lb |
| 2x6 | 12.8 lb | 19.3 lb | 25.7 lb |
| 2x8 | 16.9 lb | 25.4 lb | 33.8 lb |
| 2x10 | 21.6 lb | 32.4 lb | 43.2 lb |
| 2x12 | 26.3 lb | 39.4 lb | 52.5 lb |
| 4x4 | 19.1 lb | 28.6 lb | 38.1 lb |
Dressed size, species and moisture
Three numbers decide what a board weighs, and the first one catches almost everyone. Lumber is named by its rough sawn size and sold planed, so a 2x6 measures 1.5 by 5.5 inches. That is 8.25 square inches of section rather than 12, about 31 percent less wood than the name implies. Every weight calculation starts from the dressed dimensions.
Species is the second. Published densities at the 19 percent moisture content of kiln dried framing run from about 23 pounds per cubic foot for western red cedar to 36 for southern yellow pine. Between spruce-pine-fir at 28 and southern yellow pine, the same order differs by nearly 30 percent, which is the difference between one trip and two.
Water is the variable nobody plans for
Moisture is the third number and the one that changes most. Kiln dried framing leaves the mill at 19 percent moisture content or less. Green lumber straight off the saw holds free water in the cell cavities and can weigh 40 to 50 percent more. Pressure treated stock is soaked with waterborne preservative under pressure and comes off the truck roughly 30 percent heavier than it will be a month later on the deck.
That matters twice. On the way home it decides whether a load fits the payload on the door jamb sticker, which is the combined weight of occupants and cargo and not the badge on the tailgate. On the structure it matters because treated joists carry their wet weight from the day they are set, and they shrink as they dry, which is why treated decking is laid tight and opens to a gap rather than the other way around.
What this calculator leaves out
Engineered products, which have their own published weights: an LVL, an I-joist and a glulam are all denser or lighter than sawn lumber of the same depth. It does not cover sheet goods, hardware, or the banding and dunnage on a unit of lumber. Density varies within a species by growth ring density and grade, so treat the result as a planning figure rather than a scale reading, and it does not account for rain soaking a stack on site, which can add substantially to an open pile.
Mistakes that cost money
- Sizing a load from nominal dimensions: a 2x6 is 1.5 by 5.5 in, so nominal math overstates the wood by about 31 percent.
- Buying treated lumber and loading it like dry stock; it comes off the truck a third heavier and can put a half ton over payload.
- Reading payload off the tailgate badge. A half ton badge is a trim name, not a rating; the door jamb sticker has the real number.
- Forgetting that passengers and a full toolbox come out of payload before any lumber goes on.
- Stacking 16 ft boards in a 6 ft bed with no flag or support; overhang past 4 ft needs a red flag in most states and sags without a rack.
- Using dry weights for a deck dead load check. Treated joists sit wet for weeks and the framing carries that weight from day one.
Key facts
- A kiln dried 8 ft 2x4 in spruce-pine-fir weighs about 8.2 lb; the same board in southern yellow pine weighs about 10.5 lb.
- Dressed lumber is smaller than its name: a 2x6 measures 1.5 by 5.5 in, which is 31 percent less wood than the nominal 2 by 6.
- Green lumber can weigh 40 to 50 percent more than kiln dried, and freshly treated lumber about 30 percent more, until it dries.
- Published densities at 19 percent moisture run about 23 lb per cubic foot for western red cedar to 36 for southern yellow pine.
- A half ton pickup typically has a payload near 1,500 lb, which is about 180 kiln dried 8 ft 2x4s before passengers and tools.
Frequently asked questions
How much does a 2x4 weigh?
An 8 ft kiln dried 2x4 in spruce-pine-fir weighs about 8.2 lb, and about 10.5 lb in southern yellow pine. A pressure treated 8 ft 2x4 in southern yellow pine is closer to 13.7 lb until it dries.
Why is treated lumber so much heavier?
The preservative is waterborne and forced in under pressure, so the board leaves the plant saturated. It typically weighs about 30 percent more than the same dry board and sheds most of that water over the following weeks.
How much lumber fits in a pickup?
About 1,500 lb in a typical half ton and 2,000 in a full size, from the door jamb sticker rather than the badge. That is roughly 180 kiln dried 8 ft 2x4s, less whatever the passengers and tools weigh.
Is board footage the same as weight?
No. Board feet are a nominal volume measure used for pricing, calculated from the rough sawn size. Weight comes from the actual dressed dimensions, so a board always weighs less than its board footage suggests.
Sources and references
- Wood Handbook, Chapter 4 physical properties and moisture relations of wood (USDA Forest Products Laboratory)
- National Design Specification supplement, species and dimension data (American Wood Council)
- Chapter 5 Floors, framing member dimensions, 2021 IRC (ICC)
Next steps for this project
The usual order for a framing, decks & fences project. See all framing, decks & fences calculators.
Results are estimates based on standard formulas and typical product specifications. Confirm quantities with your supplier and local code before ordering.