Lumber Calculator
How many cubic meters in lumber and board: calculate by cross-section and length, convert pieces to m³ and back. Timber cubage.
Thickness of beam or board, mm
Cross-section width, mm
Length of one piece, m
Number of pieces of lumber
Calculation formula
V₁ = (t × w × L) / 1,000,000 V = N × V₁ N = ⌈V / V₁⌉
t — thickness in mm, w — width in mm, L — length in meters. We divide by one million to convert mm²·m into m³. When calculating pieces from a target volume, the result is rounded up: you cannot buy half a board.
About the lumber calculator
The lumber calculator computes the cubage of timber by cross-section and length: in a single click it converts pieces into cubic meters and vice versa. It is a handy cubage tool for receiving boards, beams, and battens right at the construction site.
Enter thickness and width in millimeters, length in meters. The tool calculates the volume of one piece using the formula t × w × L and multiplies by the quantity. In the «m³ → pieces» mode the result is rounded up: nobody sells half a board.
The calculator works fully in your browser and supports any sawn timber: 100×100, 150×150, 200×200 beams, edged boards, flooring and decking, battens for sheathing. The result matches GOST 6564 and standard sawmill practice.
Benefits
Two modes
Pieces to m³ and m³ to pieces in one tool
Any cross-section
Beam, batten, board — just enter thickness, width, length
Volume per piece
See the cubage of a single item right away for receiving
Frequently asked questions
What is the difference between edged and unedged board?
An edged board is sawn on all four sides and has straight edges — its width is uniform along the entire length and the cubage is calculated by nominal cross-section. An unedged board is sawn only on the top and bottom, the edges still carry wane and bark, so it is measured by the average width of each piece or with a coefficient of 0.7–0.8.
How do I calculate the cubage of slab wood?
You cannot get exact cubage of slab wood (gorbyl) with the geometric t × w × L formula because of its rounded cross-section. In practice people use the average width of the sawn part and average thickness, or apply a 0.5 conversion factor from stack volume to solid volume. Sawmills often sell slab wood by stacked cubic meters, not solid ones.
What is the difference between a beam (brus) and a batten (brusok)?
It is a question of size: a beam is sawn lumber with cross-section larger than 100×100 mm — for example 150×150, 200×200, 100×150. A batten has a section smaller than 100×100 mm, usually 50×50, 40×60, 25×50, and is used for sheathing, light rafters, and furniture parts. The cubage formula is identical for both.
How do moisture and shrinkage affect the calculation?
Green lumber shrinks during drying: shrinkage across thickness and width is 3–7%, along the length less than 0.1%. If you buy green boards, the actual volume after drying will be 5–8% less than the calculated one. Add this margin to your order or buy kiln-dried lumber (8–12% moisture).