Plywood Calculator
Sheet count for floors, walls and sheathing.
Lumber & Materials
Lumber Weight Calculator
Weight of dimensional lumber by species, size and moisture content, for load and transport planning.
Your result
Sample values1,344
Pounds total
33.6
Pounds per piece
0.67
Tons
640
Board feet
40 pieces of 2 × 8 × 12 ft Douglas fir, kiln dried.
Weight by moisture content
| Condition | Total weight |
|---|---|
| Kiln dried, 15% | 1,344 lb |
| Air dried, 19% | 1,392 lb |
| Green, 35% | 1,728 lb |
| Freshly treated | 2,016 lb |
How to use this calculator
Pick the nominal size, enter the piece length and how many you are buying. Nominal sizes are not actual — a 2 × 8 is really 1.5 by 7.25 inches — and the calculation uses the actual dimensions.
Set the moisture content honestly, because it is the largest variable here. Freshly pressure treated lumber is saturated with preservative solution and can weigh fifty percent more than the same board kiln dried, which matters a great deal when you are estimating a trailer load or a temporary support.
Formula
Volume = Actual width × Actual thickness × Length
Weight = Volume × Density at moisture content
Board feet = Nominal width × Nominal thickness × Length ÷ 12
- Actual
- a 2 × 8 is 1.5 × 7.25 in
- Density
- varies by species and moisture
Board feet use nominal dimensions; weight uses actual ones.
Worked example
Forty 2 × 8 × 12 ft Douglas fir joists, kiln dried.
- Actual section: 1.5 in × 7.25 in = 10.9 in²
- 10.9 in² ÷ 144 = 0.0755 ft² of section
- 0.0755 ft² × 12 ft = 0.906 ft³ per piece
- Douglas fir at 15% moisture: 37 lb/ft³
- 0.906 × 37 = 33.6 lb per piece
- 33.6 × 40 pieces = 1,344 lb
1,344 lb, about 0.67 tons
Understanding your results
This figure matters most for transport and temporary loading. Two-thirds of a ton is beyond the payload of many half-ton pickups once you add passengers, and stacking it on a partly built deck or a scaffold concentrates that weight on a small area. Check both the vehicle rating and what you are stacking it on.
Weight also changes after delivery. Green or freshly treated lumber loses a substantial fraction of its weight over the first few months as it dries, and it shrinks and moves as it does. That is why treated deck boards are usually spaced tight when installed wet — the gaps open up on their own.
Questions
About this calculator
Those are the rough sawn dimensions before the board is dried and planed smooth on all four faces. The finished size is 1.5 by 3.5 inches. The nominal name stuck because it is how the timber is ordered and how board feet are counted.
Freshly treated boards can weigh forty to fifty percent more than kiln dried, because they are saturated with waterborne preservative. Most of that is water and it dries out over a few months, but on delivery day it is real weight you have to carry.
A volume measure: one square foot of surface at one inch of nominal thickness, or 144 cubic inches. Hardwood is usually priced by the board foot, while dimensional softwood is priced by the piece, so it mainly matters when buying hardwood.
Among common framing species, southern yellow pine and Douglas fir are the denser options, with SPF and hem-fir noticeably lighter. Cedar is lighter again, which is part of why it is used for fencing and siding where weight and rot resistance both matter.
Keep going
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Estimates, not specifications.
Results are based on the values you enter and on typical material
properties. Densities, coverage rates and product sizes vary between
suppliers, so confirm quantities against your supplier's data before
ordering. Structural work must be signed off by a qualified
professional and meet your local building code.