Lumber Weight Calculator (kg/m³)

The calculator takes millimeters and meters, so convert from the actual dressed size, not the name on the tag. A 2x4 is 1-1/2 × 3-1/2 in, which you enter as 38.1 × 88.9 mm; a 2x6 is 1-1/2 × 5-1/2 in (38.1 × 139.7 mm). An 8 ft stud is 2.4384 m, a 12 ft board 3.6576 m.

A 2x4x8 tallies 5.33 board feet on an invoice, but the wood in it is only 1.5 × 3.5 × 96 / 144 = 3.5 board feet — 65.6% of the nominal figure. Weight follows the real volume. Rough 4/4 hardwood is tallied close to its rough size, so there the tally is a fair proxy for volume. Run the tally itself in the Board feet calculator.

US purchasing runs on board feet, so here is what one weighs. Figures use the calculator's own species densities (dry ≈ 12% moisture) and its green factor of ×1.5. One board foot = 144 in³ = 0.00236 m³.

Applied to dimension lumber tallied in nominal board feet, these overestimate by about half.

A 200-piece lift of 2x4x8 pine. Enter 38.1 × 88.9 mm, length 2.4384 m, quantity 200, species pine (500 kg/m³). Volume per piece: 0.0381 × 0.0889 × 2.4384 = 0.00826 m³, so each stud weighs 4.13 kg (9.11 lb) dry. The lift: 826 kg (1,821 lb). The same lift green: 6.19 kg (13.65 lb) per stud, 1,239 kg (2,731 lb) total. Lift counts vary by mill; check the tally.

Now the pickup. With 1,800 lb of usable payload, the payload field returns 197 dry studs but only 131 green ones. By contrast, 120 bf of 4/4 red oak at 3.90 lb/bf is 468 lb (212 kg). Sheet goods are dense: one 4×8 sheet of 23/32 in plywood (18.26 mm, 540 kg/m³) is 64.6 lb, and 3/4 in MDF (750 kg/m³) is 93.7 lb.

The dry setting assumes about 12% moisture content. Below fiber saturation, weight scales with (1 + MC); shrinkage shifts volume slightly, so treat these as close estimates.

• Framing lumber stamped KD19 or S-DRY may be up to 19% MC: 1.19 / 1.12 = about 6% heavier than the dry result.
• Furniture-grade kiln-dried hardwood at 8%: 1.08 / 1.12 = about 4% lighter.
• Air-dried stock stored outdoors usually levels off around 15–20% MC, so it lands between the dry and green results.
• Fresh-sawn or wet-stored wood: use the green setting (×1.5).

If the moisture is unknown, measure a few boards and convert with the Moisture content rather than guessing.

1. Entering nominal dimensions. Typing 2 × 4 in as 50.8 × 101.6 mm overstates a 2x4 by 52%.
2. Converting nominal board feet straight to weight. An invoice for 10 MBF of 2x4s holds only about 6.6 MBF of actual wood.
3. Using the payload figure wrong. A pickup's payload on the door-jamb sticker includes passengers, the rack and tools. Subtract them before you load lumber.
4. Treating pressure-treated lumber as dry. Treated lumber often arrives wet from the treating process. Use the green setting until it has dried.
5. Forgetting the trailer's own weight. For a trailer, the payload you can carry is the GVWR minus the empty weight of the trailer, not the GVWR alone.

1. Write the cut list in actual dimensions, not nominal sizes.
2. Tally board feet for pricing; keep the actual-volume figure separately for weight.
3. Run each species and moisture state through the calculator, then add the results.
4. Check the total against the vehicle: pickup payload, trailer GVWR minus tare, or truck freight capacity.
5. Split the delivery if the load is over the limit, rather than counting on rounding.

At truckload scale, moisture decides whether a load fills its space or its weight limit first. A flatbed carrying roughly 45,000 lb of freight holds about 11.5 MBF of dry red oak but only 7.7 MBF green. Dry pine at 2.60 lb/bf needs 17.3 MBF to reach the limit, so volume often runs out first. Cube-Out vs Weigh-Out: Which Limit Stops Your Container First? walks through that trade-off.