FBM, Cunit, Stere and Cord: Timber Units That Matter in Trade
Board foot and MBF, the pulp cunit, stere vs solid cubic metre, the firewood cord and Hoppus units — exact conversions through true cubic metres and where each unit is used.
One industry, two measurement worlds
Lumber trade speaks board feet — 1 BF = 144 in³ = 0.00236 m³, sold per MBF (thousand board feet, 2.36 m³) in North America, with pulp quoted per cunit (100 ft³ = 2.83 m³). Roundwood and firewood trade speaks stacked volume: the stere (1 m³ stacked) and the cord (128 ft³ = 3.62 m³ stacked). True cubic metres sit underneath everything as the common denominator.
Board foot and price conversion
A price per MBF converts by dividing: 500 $/MBF ÷ 2.36 = 211.9 $/m³. The reverse multiplies: 250 €/m³ × 2.36 = 589.9 €/MBF. Comparing a $/MBF quote from North America with a €/m³ quote from Europe without this step is how deals quietly lose 5–10% — and the currency is the smaller half of the trap.
Stere vs solid cubic metre
A stere (raummeter, rm) is one cubic metre of stacked wood — air gaps included. Solid content runs 0.65–0.75 for clean straight billets, less for crooked rounds, so 1 stere ≈ 0.7 m³ solid is a fair planning number. German trade splits the language: Festmeter (fm) means solid cubic metre, Raummeter means stacked. Always ask which one a price refers to — a 20% gap decides margins.
Cord and Hoppus units
The cord is 4 × 4 × 8 ft = 128 ft³ = 3.62 m³ stacked, solid content typically 2.4–2.7 m³. On the roundwood side, Hoppus units persist in teak and plantation trade: 1 Hoppus foot ≈ 0.0361 m³ true, 1 Hoppus ton = 50 h ft³ ≈ 1.80 m³ true, and 1 Hoppus m³ = 1.273 true m³ (Hoppus Formula Explained: Quarter-Girth Log Measurement has the full story).
Anchor table
| Unit | True m³ equivalent |
|---|---|
| 1 BF | 0.00236 m³ |
| 1 MBF | 2.36 m³ |
| 1 cunit (100 ft³) | 2.83 m³ |
| 1 cord (stacked) | 3.62 m³ stacked ≈ 2.4–2.7 m³ solid |
| 1 stere (stacked) | 1.00 m³ stacked ≈ 0.65–0.75 m³ solid |
| 1 Hoppus ton | ≈ 1.80 m³ true |