Volume converter
Convert volume units between liters, gallons, cups, milliliters, cubic inches, and more.
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Common volume units
Liter (L)
Definition: A liter (symbol: L) is a metric unit of volume equal to one cubic decimeter (1 dm³), or 1,000 cubic centimeters. One liter of water has a mass of approximately one kilogram at 4 °C.
History/origin: The liter was introduced in France in 1795 as part of the metric system and originally defined as the volume of one kilogram of water. Although not an SI base unit, it is accepted for use with SI and is widely used worldwide.
Current use: Liters are the standard unit for measuring liquid volume in most countries. Beverages, fuel, cooking liquids, and medical fluids are all commonly measured in liters or milliliters.
US gallon (gal)
Definition: The US gallon (symbol: gal) is a unit of volume equal to exactly 3.785411784 liters, 4 quarts, 8 pints, or 128 US fluid ounces. It differs from the imperial gallon used in the UK, which is approximately 4.546 liters.
History/origin: The US gallon is based on the old English wine gallon. When the United States became independent, it retained the wine gallon rather than adopting the imperial gallon that the UK later standardized in 1824, creating a permanent difference between the two systems.
Current use: The US gallon is used in the United States for fuel, large beverage containers, and industrial liquids. It is also used in some Latin American countries for fuel pricing.
Milliliter (mL)
Definition: A milliliter (symbol: mL) is one thousandth of a liter (0.001 L). It is exactly equal to one cubic centimeter (1 cm³), making it a practical unit for small liquid volumes.
History/origin: The milliliter follows from the liter and the metric prefix "milli-" (1/1000). Its equivalence to 1 cm³ was recognized early and makes it especially useful in science, where volume and displacement are closely related.
Current use: Milliliters are standard for medicine doses, cooking measurements, perfume, and small beverage sizes. Syringes, measuring spoons, and nutrition labels typically express volumes in milliliters.
US fluid ounce (fl oz)
Definition: A US fluid ounce (symbol: fl oz) is a unit of volume equal to 1/128 of a US gallon, or approximately 29.5735 milliliters. It is distinct from the imperial fluid ounce (28.4131 mL) used in the UK.
History/origin: The fluid ounce developed in England as a volume measure equivalent to the volume occupied by one avoirdupois ounce of water. The US and British versions diverged when the US retained the older wine gallon as its gallon standard.
Current use: US fluid ounces are used on beverage containers, nutrition labels, and cooking recipes in the United States. A standard US can of soda is 12 fl oz, and a US coffee cup is typically 8 fl oz.
Volume conversion table
| From | To | Result |
|---|---|---|
| 1 Liter (L) | US gallons (gal) | 0.2642 gal |
| 1 US gallon (gal) | Liters (L) | 3.7854 L |
| 1 Liter (L) | Milliliters (mL) | 1000 mL |
| 1 Liter (L) | US fluid ounces (fl oz) | 33.814 fl oz |
| 1 US fluid ounce (fl oz) | Milliliters (mL) | 29.5735 mL |
| 1 US cup (cup) | Milliliters (mL) | 236.588 mL |
| 1 Imperial gallon (gal) | Liters (L) | 4.5461 L |
| 1 US pint (pt) | Milliliters (mL) | 473.176 mL |
| 1 Cubic meter (m³) | Liters (L) | 1000 L |
| 1 Cubic foot (ft³) | Liters (L) | 28.3168 L |
How to convert volume units
Volume conversions multiply the value by a fixed factor. Note that US and imperial units share the same names (gallon, pint, fluid ounce) but have different sizes, so always verify which system you are using.
Liters to US gallons
gallons = liters × 0.2641720524
Example: 20 L = 20 × 0.2641720524 = 5.283 gal
US gallons to liters
liters = gallons × 3.785411784
Example: 5 gal = 5 × 3.785411784 = 18.927 L
Milliliters to US fluid ounces
fl oz = mL × 0.0338140227
Example: 500 mL = 500 × 0.0338140227 = 16.907 fl oz
Frequently asked questions
How many liters are in a gallon?
It depends on which gallon. A US liquid gallon equals 3.785 liters. A UK imperial gallon equals 4.546 liters — about 20% larger. Always confirm which gallon is being used, especially for fuel economy comparisons: a car rated at 40 MPG in the UK gets the equivalent of about 33 MPG by US gallon standards.
How many ml are in a fluid ounce?
A US fluid ounce equals 29.574 mL. A UK imperial fluid ounce equals 28.413 mL — slightly smaller. For most practical purposes the difference is negligible, but it matters in precise formulation work. A standard US can of soda is 12 fl oz = 355 mL; a UK pint of beer is 20 imperial fl oz = 568 mL.
How many cups are in a liter?
Using the US cup (240 mL), 1 liter equals approximately 4.167 cups. Using the metric cup (250 mL, common in Australia and Canada), 1 liter equals exactly 4 cups. For US recipes, 4 cups is close enough for most liquid measurements; for precision, use 4.167 cups or measure in mL.
How do I convert milliliters to liters?
Divide the milliliter value by 1,000. For example, 500 mL = 0.5 L, 250 mL = 0.25 L, 1,500 mL = 1.5 L. To convert liters to milliliters, multiply by 1,000. This is a simple metric prefix conversion — 'milli' means one thousandth.
What is the difference between a US pint and a UK pint?
A US pint equals 473 mL (16 US fluid ounces). A UK imperial pint equals 568 mL (20 imperial fluid ounces) — about 20% larger. This is why a pint of beer in a British pub is noticeably larger than a pint in the US. When a recipe calls for a pint, check whether it originates in the US or UK.
How many milliliters are in a cup, tablespoon, and teaspoon?
1 US cup = 240 mL (or 236.6 mL precisely). 1 tablespoon = 14.79 mL (commonly rounded to 15 mL). 1 teaspoon = 4.93 mL (commonly rounded to 5 mL). These rounded values — 240 / 15 / 5 — are the standard working figures used in most metric recipe conversions.
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