Imperial Fluid Ounces (imp-fl-oz) to Kannor (kanna) conversion

What is the Imperial Fluid Ounce?

The imperial fluid ounce is a unit of volume in the British imperial system, used chiefly in the United Kingdom and Commonwealth countries for measuring liquids. It is slightly smaller than the US fluid ounce.

Definition

The imperial fluid ounce is defined as one one-hundred-sixtieth of an imperial gallon.

$$1\ \text{imp-fl-oz} = 0.0284131\ \text{l}$$

Since the imperial gallon is exactly 4.54609 litres, the imperial fluid ounce is exactly $4.54609 \div 160 = 28.4130625$ mL, a factor the NIST Guide to the SI records as 2.841 306 × 10⁻⁵ m³. There are 20 imperial fluid ounces in an imperial pint and 160 in an imperial gallon.

Origin and History

The fluid ounce descends from the medieval practice of relating volume to the weight of a substance—historically, one fluid ounce of water was intended to weigh about one avoirdupois ounce. The British imperial system was standardized by the Weights and Measures Act of 1824, which fixed the gallon as the volume occupied by 10 pounds of distilled water. The imperial gallon was later redefined in metric terms as exactly 4.54609 litres in 1985.

Law and Notable Facts

The imperial fluid ounce remains a legally recognized unit in the UK, though most packaged goods are now labeled in millilitres. Notably, the imperial fluid ounce (28.413 mL) is about 4% smaller than the US customary fluid ounce (29.574 mL), so an imperial pint (568 mL, 20 fl oz) is noticeably larger than a US pint (473 mL, 16 fl oz)—a frequent source of confusion for travelers.

Real-World Examples and Conversions

• A traditional British pint of beer is 20 imperial fluid ounces, or about 568 mL.
• A 5 imperial-fluid-ounce cup of tea equals roughly 142 mL.
• 10 imperial fluid ounces is exactly half an imperial pint, about 284 mL.
• Converting a US recipe: 8 US fluid ounces (236.6 mL) equals about 8.33 imperial fluid ounces.

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.