Convert between different units of volume including metric and imperial measurements such as liters, milliliters, gallons, fluid ounces, and more.
The liter was originally defined as the volume of 1 kilogram of pure water at standard atmospheric pressure and temperature. Today, it's exactly equal to one cubic decimeter (dm³).
A US gallon (≈3.785 liters) is smaller than an Imperial gallon (≈4.546 liters). This difference causes confusion when comparing fuel efficiency between countries that use different systems.
In cooking, volume measurements can vary by region. A US cup is 237 mL, while a metric cup is 250 mL. Australia and New Zealand standardized their cup measurements to 250 mL in the 1970s.
The oil industry measures volume in barrels. One barrel of oil equals 42 US gallons (approximately 159 liters). This unit dates back to the early days of oil production when wooden barrels were used for transport.