Board Feet (board-foot) to Kannor (kanna) conversion

What is the Board Foot?

The board foot is a unit of volume used in North America to measure sawn lumber and hardwood. It represents a piece of wood one foot long, one foot wide, and one inch thick.

Definition

A board foot is defined as exactly 144 cubic inches — the volume of a board 12 in × 12 in × 1 in.

$$1\ \text{board-foot} = 2.35974\ \text{l}$$

Equivalently, one board foot equals $\frac{1}{12}$ cubic foot — the NIST Guide to the SI puts the cubic foot at exactly 2.831685×10⁻² m³ — or 2,359.74 cubic centimetres.

Origin and History

The board foot arose in the 19th-century American and Canadian lumber trade as a practical way to price rough-sawn timber by wood content rather than by finished dimensions. Because a "1-inch" board and a "12-inch" width refer to nominal (pre-planing) sizes, the board foot standardized how mills, wholesalers, and builders quoted and sold lumber. It remains the customary trade unit in the United States and Canada today.

Law and Notable Facts

The board foot is recognized in U.S. and Canadian lumber commerce and standards, where large volumes are quoted in "thousand board feet" (MBF), with M denoting the Roman numeral for 1,000. Board-foot content is calculated from nominal dimensions, so a nominal "2×4" (actually about 1.5 in × 3.5 in when surfaced) is still counted at its nominal 2 in × 4 in size — meaning the buyer pays for wood removed during planing. Rough-sawn hardwoods are commonly measured in "quarters" of nominal thickness (4/4, 5/4, 8/4).

Real-World Examples and Conversions

• A board 8 ft long × 6 in wide × 1 in thick contains $\frac{8 \times 6 \times 1}{12} = 4$ board feet.
• A nominal 2×4 stud 8 ft long counts as $\frac{2 \times 4 \times 8}{12} \approx 5.33$ board feet.
• One thousand board feet (1 MBF) equals about 2.36 cubic metres of wood, a typical way to price bulk lumber shipments.
• One board foot equals roughly 2.36 litres, so a small stack of ten board feet holds about 23.6 litres of wood volume.

What is Kannor?

Kannor is the plural of kanna, an old Swedish unit of volume used for both liquids and dry goods before Sweden adopted the metric system. It was one of the most common everyday measures in Sweden for centuries, especially for spirits and other liquids.

Definition of Kanna

Following the Swedish measurement regulations of 1665, one kanna was standardized at approximately 2.617 litres.

$$1 \text{ kanna} \approx 2.617 \text{ L} = 2617 \text{ mL}$$

The kanna was part of a coherent system of Swedish volume units. Its subdivisions and multiples included:

• 1 kanna = 2 stop
• 1 kanna = 8 kvarter
• 1 kanna = 32 jungfrur
• 1 kanna = 1/48 tunna (barrel)

Origin and Formation

The kanna originated as a practical measure tied to common containers used for storing and transporting goods. Sweden brought its many local measures under a single national standard with the ordinances of 1665, which fixed the kanna at about 2.617 litres. The unit was used throughout Sweden (and Finland, then part of the Swedish realm) for trade in liquids such as beer, milk, and spirits, as well as for some dry goods.

Historical Significance and Usage

For more than two centuries the kanna was a mainstay of Swedish commerce and daily life. Merchants, brewers, and farmers measured and sold goods by the kanna and its subdivisions. The unit was gradually phased out as Sweden transitioned to the metric system, which became mandatory in 1889. After that, litres replaced kannor in everyday and legal use.

Conversions

Using the 1665 value of 2.617 litres:

• 1 kanna ≈ 2.617 litres
• 1 kanna ≈ 0.691 US gallons
• 1 kanna ≈ 0.576 Imperial gallons
• 100 kannor ≈ 261.7 litres

To convert a volume in kannor to litres:

$$\text{Volume in Liters} = \text{Volume in Kannor} \times 2.617$$

Laws and Associated Figures

The kanna was defined by Swedish royal measurement ordinances rather than by any single individual. Its standardization in 1665 and its eventual replacement by the metric system in 1889 reflect Sweden's long effort to bring consistency to weights and measures.