Lumber Volume Calculator — m, cm to m³, dm³, cost
How to use this calculator
Enter lumber dimensions — thickness, width, and length — in your preferred metric unit (m, cm, or mm). Use Single Piece for one board, Multiple Pieces for a cut list, or Common Lumber for European structural timber sizes (38×89, 45×145, …) per EN 336. The m³ figure is what your timber merchant quotes against.
Formula: Volume (m³) = Thickness (m) × Width (m) × Length (m). Results are shown in both cubic meters and cubic decimeters (1 m³ = 1000 dm³).
Saved Calculations
| Time | Mode | Size | Length | Qty | m³ | Cost |
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How to Calculate Lumber Volume (Metric)
Timber is traded by the cubic metre. This tool converts thickness, width and length into m³ and dm³ (1 m³ = 1000 dm³) for single pieces, a cut list, or standard target sizes. Enter dressed (planed) dimensions for delivered timber; enter sawn target sizes when buying rough stock, since the m³ price usually refers to the sawn size per EN 1313. Add 10–15% for cutting waste before ordering.
Formula
V (m³) = T(m) × W(m) × L(m), multiplied by piece count. With T and W in mm and L in m: V = (T/1000) × (W/1000) × L. Example: a 45 × 145 mm × 3 m stud = 0.0196 m³ ≈ 19.6 dm³.
European Structural Timber (EN 336) & Field Use
Structural softwood follows EN 336 target sizes — 38×89, 45×145, 45×195 mm and posts from 70×70 to 120×120 mm — graded to strength class C16/C24 under EN 14081 and designed to Eurocode 5. Size joists with the floor joist span calculator, frame decks with the deck calculator and walls with the stud wall calculator, then total the order here. For fencing use the fence calculator and for sheet goods the plywood & OSB calculator.
Weight Estimation
Weight is estimated at about 500 kg/m³ for kiln-dried softwood (spruce, pine, ~12% MC). Green timber is heavier; hardwoods such as oak run 650–750 kg/m³, while cedar is lighter at around 350 kg/m³.
FAQ
Sawn or planed size? The m³ price typically quotes the sawn target size; the delivered planed section is a few mm smaller. Enter whichever matches the price you were given.
How much waste? 10–15% for framing offcuts, ~10% for sheathing.
What is a "lineal metre" price? Switch the cost mode to per-piece and divide accordingly, or convert: price/m³ = price/m ÷ (T×W in m²).
At the timber merchant
2025 EU pricing per m³: C16/C24 structural softwood €220–360/m³, kiln-dried planed sections €350–500/m³, pressure-treated €420–620/m³, European oak €1,400–2,200/m³, beech €900–1,300/m³. Per piece for reference: 45×145×3 m stud €9–14, 45×195×4 m joist €22–32, 28×145×3.6 m treated decking €11–18. The number-one merchant mistake is ordering against the dressed (planed) section when the price card uses the sawn target size — always confirm which size the quote refers to. For sized members rather than raw volume, design joists with the joist span calculator and verify framing schedules to Eurocode 5; merchants typically deliver in 0.3 m length increments, so round each length up before totalling.
