Liters (L)

What is a liter?

The liter (also spelled litre) is the everyday metric unit of volume, equal to exactly one cubic decimeter, or 1,000 cubic centimeters. It is accepted for use with the SI, and its symbol is L (or l).

A liter is a little more than a US quart (1 L ≈ 1.057 qt) and a little less than an imperial quart. A cube 10 cm on each side holds exactly one liter, and a liter of water has a mass of almost exactly one kilogram.

What liters are used for

• Drinks: bottled water, soda and milk
• Fuel sold by the liter outside the US
• Engine displacement (a 2.0 L engine)
• Backpack, fridge and luggage capacity
• Fuel economy in liters per 100 km

Liters in real life

• A large bottle of soda holds 2 L
• A car fuel tank holds about 50 L
• An adult human body contains about 5 L of blood
• A standard bathtub holds about 150 L
• A typical carry-on backpack is 30–40 L

One liter is enough to fill about 2.8 soda cans, or enough to fill about 1.3 wine bottles, or enough to fill about 23 shot glasses, or about 26% of a gallon jug of milk.

History of the liter

The liter was introduced in France in 1795 as the volume of a cubic decimeter. From 1901 to 1964 it was defined as the volume of one kilogram of water, which made it about 28 parts per million larger than a cubic decimeter. In 1964 it was returned to exactly 1 dm³. The capital-L symbol was approved in 1979 to avoid confusion between l and the digit 1.