Volume units multiply fast once you cross between metric, US customary, and imperial systems, this converter spans all 21 in one searchable tool, so converting from milliliters to UK gallons or teaspoons to megaliters takes one lookup instead of a chain of separate conversions.
How to use this volume unit converter
- Enter a value in the From field.
- Search and select your From unit and To unit using the searchable dropdowns.
- Read the converted result instantly, or tap Swap Units to reverse the direction.
What this volume unit converter covers
This tool spans 21 volume units across three measurement systems: the metric system (milliliters up to megaliters), US customary units (teaspoons up to gallons), and imperial/UK units, which sometimes differ in size from their US namesakes despite sharing the same name.
Why US and UK units of the same name differ
A UK (imperial) gallon is larger than a US gallon, 4.54609 liters versus 3.78541 liters, a difference of roughly 20%. This gap carries through to pints, quarts, and fluid ounces too, since they’re all defined as fractions of their respective gallon. Recipes, fuel economy figures, and product labels from the UK, Canada, Australia, or older Commonwealth sources can use the imperial definition even when the unit name looks identical to its US counterpart, which is why picking the correct regional unit matters for an accurate conversion.
Frequently asked questions
Why is a UK gallon different from a US gallon?
They’re defined differently by volume: a UK (imperial) gallon is 4.54609 liters, while a US gallon is 3.78541 liters, roughly 20% smaller. This size difference also carries through to pints, quarts, and fluid ounces in each system.
How many volume units does this converter support?
21 units spanning the metric system (milliliters to megaliters), US customary units (teaspoons to gallons), and imperial/UK units.
