The US liquid quart equals 946 millilitres — 2 pints or 1/4 US gallon. The UK imperial quart (1.137 L) is larger, like the other UK liquid units. Quarts are used in US cooking recipes and for motor-oil bottles.
Real-world: A US quart of motor oil is 946 ml. A "quart of milk" in the US ≈ 1 L. UK "quart" is rare today.
Read full quart reference →The US gallon equals 3.785411784 litres exactly. It is the standard fuel and liquid volume unit in the United States. A typical American car holds 14–18 US gallons of fuel. US fuel economy is quoted in miles per US gallon (mpg).
Real-world: US car tank ≈ 15 gallons (57 L). 1 US gallon of milk is a common grocery size (3.79 L). US paint often sold by the gallon.
Read full us gallon reference →