How to use the Volume Converter
- Type the value you want to convert.
- Choose the unit you are converting from, then the unit you want.
- Read the converted value and the conversion rate.
- Use the reference table to see common quantities in the same units.
Formula used
Result = Value × (litres per source unit ÷ litres per target unit). 1 US gallon = 3.785411784 L, 1 UK gallon = 4.54609 L, 1 US cup = 236.5882365 ml.
Worked example
Here is the Volume Converter worked through with the example values shown above, so you can check each step by hand.
| Inputs | |
|---|---|
| Value | 1 |
| From | Gallons (US) |
| To | Litres (l) |
| Result | |
| Converted value | 3.7854118 |
| Conversion rate | 1 gal = 3.7854118 l |
Quick reference table
Common values converted with the units selected above.
| From | To |
|---|---|
| 1 gal | 3.7854118 l |
| 2 gal | 7.5708236 l |
| 5 gal | 18.927059 l |
| 10 gal | 37.854118 l |
| 25 gal | 94.635295 l |
| 100 gal | 378.54118 l |
Common conversions
One US gallon is 3.7854 litres, and one litre is 0.2642 US gallons. One US cup is 236.6 ml, a tablespoon is 14.79 ml and a teaspoon is 4.93 ml. There are 3 teaspoons in a tablespoon, 16 tablespoons in a cup, 2 cups in a pint, 2 pints in a quart and 4 quarts in a gallon.
A cubic metre holds 1,000 litres, and one litre equals 1,000 millilitres. A US quart is 0.9464 litres, which is a little less than a litre.
US gallon versus UK gallon
The US and UK use different gallons. A US gallon is 3.7854 litres, and a UK (imperial) gallon is 4.5461 litres, about 20% larger. This matters for fuel economy figures and for recipes from British cookbooks, and it is why the same car has a higher miles-per-gallon figure in the UK.
Fluid ounces also differ: the US fluid ounce is about 29.57 ml and the UK one is about 28.41 ml. This converter uses US fluid ounces, cups, pints and quarts.
Cooking measurements
Cup sizes vary between countries. The US customary cup is about 236.6 ml, while the metric cup used in Australia, Canada and New Zealand recipes is 250 ml, and a UK cup in older recipes can be different again. For baking, where accuracy matters, weighing ingredients in grams is more reliable than measuring by volume, because a cup of flour can weigh different amounts depending on how it is packed.
Liquids are easier: a litre of water is about 4.23 US cups. Remember that a volume of one ingredient does not equal the same weight as another, so this converter cannot turn cups into grams.
Where volume conversions are used
People convert volume for cooking, car fuel and tank sizes, aquariums and pools, medicine doses given in ml or teaspoons, and shipping and storage. For medicine, always use the measuring device that comes with the product, and follow the label or your pharmacist’s advice rather than household spoons, which vary in size.
Large volumes are often given in cubic metres, so knowing that 1 m³ equals 1,000 litres makes it easy to estimate the water in a tank or pool.
Frequently asked questions
How many litres are in a gallon?
A US gallon is 3.785 litres and a UK gallon is 4.546 litres.
How many tablespoons are in a cup?
There are 16 US tablespoons in a US cup.
How many ml is a cup?
A US cup is about 236.6 ml. A metric cup is 250 ml.
Are US and UK pints the same?
No. A US pint is about 473 ml and a UK pint is about 568 ml. This converter uses the US pint.
How many cups are in a litre?
About 4.23 US cups.
Can I convert cups to grams?
Not with a volume converter, because it depends on the ingredient. Use a cooking conversion chart for the specific ingredient or weigh it.
This calculator gives estimates for information only. Actual figures from a bank, employer, tax authority or doctor may differ. It is not financial, tax, legal or medical advice.