Imperial Gallons (imp-gal) to Kannor (kanna) conversion

What is the Imperial Gallon?

The imperial gallon is a unit of volume used in the United Kingdom and several Commonwealth countries, most commonly for measuring fuel, beverages, and other liquids. It is noticeably larger than the US gallon.

Definition

The imperial gallon is defined as exactly 4.54609 litres:

$$1\ \text{imp-gal} = 4.54609\ \text{l}$$

This is an exact defining relation, not an approximation, and the NIST Guide to the SI lists the same value of 4.546 09 × 10⁻³ m³. The imperial gallon is also subdivided into 4 quarts, 8 pints, or 160 imperial fluid ounces, and it is about 20% larger than the US liquid gallon (3.78541 L).

Origin and History

The gallon descends from medieval English measures for wine and ale, which historically had several conflicting definitions. The imperial gallon was standardised by the British Weights and Measures Act of 1824, originally defined as the volume of 10 pounds of distilled water weighed in air at 62 °F. In 1985 the UK redefined it in exact metric terms as 4.54609 litres, aligning the traditional unit with the SI system.

Law and Notable Facts

The imperial gallon remains a legally recognised unit in the UK and countries such as Canada, though metric litres are now standard for most trade. A key point of confusion is that the imperial gallon (4.54609 L) differs from the US liquid gallon (3.785411784 L); the two share a name but are distinct units, so fuel-economy figures quoted in "miles per gallon" are not directly comparable between the UK and the US.

Real-World Examples and Conversions

• A UK fuel purchase of 10 imperial gallons is about 45.46 litres.
• A car rated at 50 miles per imperial gallon achieves roughly 41.6 miles per US gallon for the same efficiency.
• 1 imperial gallon of fresh water weighs about 4.546 kg (roughly 10 pounds), reflecting its original 1824 definition.
• 1 imperial gallon equals about 1.20095 US gallons.

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.