How to use this calculator
- Enter actual dimensions. Use the board thickness, width and length for one repeated piece.
- Set quantity. Enter how many identical boards, planks or timbers are in the load.
- Choose species or density. Use a common species density preset, or choose custom/measured stock and enter density directly.
- Check weight and board feet. Use total weight for payload/logistics and board feet for lumber-volume context.
How it works
Lumber weight starts with actual rectangular volume: V = T x W x L x N The calculator multiplies that volume by the selected species density preset or custom measured density: weight = rho x V
It also reports board feet from the standard lumber volume relation: BF = thickness(in) x width(in) x length(ft) / 12 For pure volume and cost estimating, use the board feet calculator. For sheet goods, use the plywood sheet calculator.
Worked example
Verified against the live calculator
Ten 1 in x 6 in x 8 ft boards at a custom 600 kg/m^3
total 40 board feet. The volume is about 3.33 ft^3,
so the total weight is about 56.6 kg, or roughly
125 lb.
Frequently asked questions
How do you calculate lumber weight?
Multiply the actual board volume by the wood density. For rectangular lumber, volume is thickness times width times length times quantity.
Should I use nominal or actual lumber dimensions?
Use actual dimensions for payload, shipping or structural material weight. Enter nominal sizes only if you intentionally want a rough nominal estimate.
Why does wood density vary so much?
Species, grade, moisture content, treatment, defects and product type all affect density. Use a species preset for screening, or choose custom/measured stock when payload, shipping or rack loading matters.
Is this the same as a board feet calculator?
No. Board feet measure volume. This calculator also converts that volume into weight using the density you enter.
Method & assumptions
- Uses actual rectangular dimensions; it does not convert nominal lumber sizes automatically.
- Species presets are screening values near air-dry stock; custom density should match species, moisture content and treatment condition.
- Board feet are reported for volume context only; they do not include waste, cuts or price.
- Payload, trailer, rack and shipping decisions still need rated capacity, load distribution, securement and local rules.