LITRE (not liter nor gallon)
Mass: Kilogram Length: Metre Capacity: Litre
By capacity, I assume you mean volume. That would be the liter.
a unit of liquid capacity equal to a quarter of a gallon or two pints
we call it millilitre. litre is the standard unit which contains 1000 millilitre. it is also called capacity
For most of the world, it's probably in Liter, a standard unit to measure capacity or space or volume. In the US, gallon is the stand for fluid capacity, but cubic feet is often used for space capacity.
volume and capacity is math
Millilitres is the standard. - 5 to a teaspoon.