What is a litre?
A litre is a metric unit of volume used for liquids and capacity. One litre is equal to 1,000 millilitres, or about 1.76 UK pints.
A litre is a metric unit of volume. It is commonly used for liquids, fuel, drinks, containers and capacity measurements.
One litre is equal to 1,000 millilitres. Litres are part of everyday metric system use, while UK users may also need to compare litres with pints and gallons.
Why litres matter
Litres are one of the most common volume units in the UK. You see them on milk, drinks, fuel, paint, cleaning products, water bottles and household containers.
Litres are also useful when comparing metric and imperial volume units. For example, a car fuel tank may be measured in litres, while older references may use gallons.
Litre conversions
Here are the litre conversions most useful for everyday unit conversion.
| Conversion | Value | Example |
|---|---|---|
| 1 litre to millilitres | 1,000 ml | 2 litres = 2,000 ml |
| 1 millilitre to litres | 0.001 litres | 500 ml = 0.5 litres |
| 1 litre to UK pints | about 1.7598 UK pints | 2 litres ≈ 3.52 UK pints |
| 1 UK pint to litres | about 0.5683 litres | 4 UK pints ≈ 2.27 litres |
| 1 UK gallon to litres | about 4.5461 litres | 10 UK gallons ≈ 45.46 litres |
Litre conversion formulas
Most litre conversions use a simple conversion factor.
litres = millilitres ÷ 1,000
UK pints = litres × 1.759754
litres = UK pints × 0.568261
litres = UK gallons × 4.54609
For everyday use, litre-to-pint results are often rounded to one or two decimal places. For recipes, science or product labelling, use the level of precision the situation needs.
Litres vs millilitres
Litres and millilitres are both metric volume units. Millilitres are better for smaller amounts, while litres are better for larger containers and totals.
| Unit | Metric relationship | Common use |
|---|---|---|
| millilitre | 1/1,000 of a litre | medicine doses, small bottles, recipes and drinks |
| litre | 1,000 millilitres | milk, fuel, water, paint, containers and household liquids |
| kilolitre | 1,000 litres | larger storage, water usage and industrial contexts |
Litres, UK pints and gallons
UK pints and gallons are not the same as US pints and gallons. That matters when converting recipes, drinks, fuel or old measurements.
1 UK gallon ≈ 4.54609 litres
1 US liquid gallon ≈ 3.78541 litres
When converting litres to pints or gallons, choose the correct UK or US unit rather than assuming all pints and gallons are identical.
Common UK uses
Litres appear in lots of everyday UK measurements.
- Fuel: petrol and diesel are sold by the litre.
- Drinks: water, juice and soft drinks often use ml and litres.
- Milk: bottles may show metric volume, while pints are still familiar to many people.
- Cooking: recipes may use millilitres, litres, teaspoons and tablespoons.
- DIY: paint, cleaning liquids and garden products often use litres.
Litre conversion examples
| Question | Calculation | Answer |
|---|---|---|
| How many ml is 2.5 litres? | 2.5 × 1,000 | 2,500 ml |
| How many litres is 750 ml? | 750 ÷ 1,000 | 0.75 litres |
| How many UK pints is 1 litre? | 1 × 1.759754 | about 1.76 UK pints |
| How many litres is 1 UK gallon? | 1 × 4.54609 | about 4.55 litres |
Rounding litre conversions
For everyday shopping, cooking or household use, one or two decimal places is usually enough. For small recipe amounts, millilitres may be clearer than litres.
For example, 0.568261 litres can be written as about 0.57 litres, or 568 ml, depending on what is easier to understand.
Quick answers
| Question | Answer |
|---|---|
| How many millilitres are in a litre? | 1,000 millilitres. |
| How many litres are in 500 ml? | 0.5 litres. |
| How many UK pints are in a litre? | About 1.76 UK pints. |
| How many litres are in a UK gallon? | About 4.546 litres. |
FAQs
What is a litre used for?
A litre is used for liquids and capacity, including fuel, drinks, milk, water, paint and household containers.
How many millilitres are in a litre?
There are 1,000 millilitres in 1 litre.
How many UK pints are in a litre?
There are about 1.76 UK pints in 1 litre.
Are UK and US gallons the same?
No. A UK gallon is about 4.546 litres, while a US liquid gallon is about 3.785 litres.
Sources
Conversion values are based on standard volume relationships, including 1 litre = 1,000 millilitres, 1 UK pint ≈ 0.568261 litres and 1 UK gallon ≈ 4.54609 litres.