What is litre?
The litre is a metric unit of volume equal to one cubic decimetre. It is widely used for measuring liquid quantities in cooking, beverages, fuel, and laboratory work across metric countries.
Real-world uses
Litres are the global standard for beverage volumes, fuel tank capacities, engine displacement, and liquid medications. Water intake recommendations are given in litres (about 2 L/day), and swimming pools are measured in thousands of litres.
History
The litre was originally defined in 1795 as one cubic decimetre. In 1901 it was redefined based on the mass of water, creating a tiny discrepancy with the cubic decimetre. In 1964, the original definition (1 L = 1 dm³ exactly) was restored.
Common mistakes
Confusing litres with liters (both are correct—"litre" is the international spelling, "liter" is American). Also, assuming 1 litre of any liquid weighs 1 kg; this is only true for water at 4°C.
What is Imperial fluid ounce?
An Imperial fluid ounce is a volume unit used in the United Kingdom equal to approximately 28.41 millilitres. It is used in British cooking recipes, beverage servings, and pharmaceutical labelling.
Real-world uses
Imperial fluid ounces are used in the United Kingdom, Canada (in some contexts), and other Commonwealth countries for beverage serving sizes and recipe measurements. A British pint is 20 Imperial fluid ounces, compared to the US pint of 16 US fluid ounces.
History
The Imperial fluid ounce was defined by the British Weights and Measures Act of 1824, which established the Imperial gallon based on the volume of 10 pounds of water at 62°F. One Imperial fluid ounce is 1/160 of that gallon.
Common mistakes
Assuming Imperial and US fluid ounces are the same. An Imperial fluid ounce is about 28.41 mL versus 29.57 mL for the US version. This means an Imperial pint (568 mL) is larger than a US pint (473 mL).
When is this conversion used?
Converting between litre and Imperial fluid ounce is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region. Fuel economy, beverage volumes, and liquid measurements frequently require converting between litres and US gallons, especially for automotive and cooking contexts across different markets.
Worked examples
1 litre = 35.19507973 Imperial fluid ounce
1 Imperial fluid ounce = 0.02841306 litre
How to convert litre to Imperial fluid ounce
To convert litre to Imperial fluid ounce, multiply the value by 35.19507973.
To convert Imperial fluid ounce back to litre, multiply by 0.02841306.
Measurement standards
The cubic metre is the SI derived unit of volume. The litre, equal to exactly one cubic decimetre (0.001 m³), is accepted by the BIPM for use alongside SI units. Both the lowercase "l" and uppercase "L" are approved symbols for the litre.
Did you know?
An Olympic swimming pool holds 2,500 cubic metres of water — about 2.5 million litres. The Amazon River discharges roughly 209,000 cubic metres per second, enough to fill 84 Olympic pools every single second.
Quick reference: litre to Imperial fluid ounce
| litre | Imperial fluid ounce |
|---|---|
| 0.1 | 3.51950797 |
| 0.5 | 17.59753986 |
| 1 | 35.19507973 |
| 2 | 70.39015946 |
| 5 | 175.97539864 |
| 10 | 351.95079728 |
| 25 | 879.8769932 |
| 50 | 1,759.75398639 |
| 100 | 3,519.50797279 |
| 250 | 8,798.76993196 |
| 500 | 17,597.53986393 |
| 1,000 | 35,195.07972785 |
Common values
| litre | Imperial fluid ounce | |
|---|---|---|
| A teaspoon | 0.005 litre | 0.1759754 Imperial fluid ounce |
| A cup of coffee | 0.25 litre | 8.79876993 Imperial fluid ounce |
| A water bottle | 0.5 litre | 17.59753986 Imperial fluid ounce |
| A bathtub | 300 litre | 10,558.52391836 Imperial fluid ounce |
| A swimming pool (Olympic) | 2,500,000 litre | 87,987,699.31963512 Imperial fluid ounce |