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 US fluid ounce?
A US fluid ounce is a volume unit equal to approximately 29.57 millilitres. It is used in the United States for beverage servings, cooking measurements, and product labelling.
Real-world uses
US fluid ounces are used for beverage labelling (a standard can of soda is 12 fl oz), cooking measurements, and cosmetics packaging in the United States. Cocktail recipes and bartending rely heavily on fluid ounce measurements (a standard shot is 1.5 fl oz).
History
The US fluid ounce derives from the English wine gallon tradition. When the US and UK diverged in measurement standards in the 19th century, their fluid ounces ended up slightly different. The US fluid ounce is defined as 1/128 of a US gallon.
Common mistakes
Confusing US fluid ounces with Imperial fluid ounces—they differ by about 4% (US: 29.57 mL, Imperial: 28.41 mL). Also, confusing fluid ounces (volume) with avoirdupois ounces (weight), which are completely different measurements.
When is this conversion used?
Converting between litre and US 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 = 33.8140227 US fluid ounce
1 US fluid ounce = 0.02957353 litre
How to convert litre to US fluid ounce
To convert litre to US fluid ounce, multiply the value by 33.8140227.
To convert US fluid ounce back to litre, multiply by 0.02957353.
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 US fluid ounce
| litre | US fluid ounce |
|---|---|
| 0.1 | 3.38140227 |
| 0.5 | 16.90701135 |
| 1 | 33.8140227 |
| 2 | 67.6280454 |
| 5 | 169.07011351 |
| 10 | 338.14022702 |
| 25 | 845.35056755 |
| 50 | 1,690.70113509 |
| 100 | 3,381.40227018 |
| 250 | 8,453.50567546 |
| 500 | 16,907.01135092 |
| 1,000 | 33,814.02270184 |
Common values
| litre | US fluid ounce | |
|---|---|---|
| A teaspoon | 0.005 litre | 0.16907011 US fluid ounce |
| A cup of coffee | 0.25 litre | 8.45350568 US fluid ounce |
| A water bottle | 0.5 litre | 16.90701135 US fluid ounce |
| A bathtub | 300 litre | 10,144.20681055 US fluid ounce |
| A swimming pool (Olympic) | 2,500,000 litre | 84,535,056.7546075 US fluid ounce |