Measurement reference
Unit Encyclopedia
Learn what common units mean, where they are used, how their symbols work, and which converters answer the next practical question.
12 units
Weight
Kilogram
The kilogram is the SI base unit of mass. It is defined by fixing the numerical value of the Planck constant.
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Weight
Pound
The international avoirdupois pound is a unit of mass defined as exactly 0.45359237 kilograms.
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Weight
Gram
A gram is one-thousandth of a kilogram and is a convenient metric unit for relatively small masses.
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Weight
Ounce
The avoirdupois ounce is a unit of mass equal to one-sixteenth of a pound. It is different from a fluid ounce, which measures volume.
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Length
Meter
The meter is the SI base unit of length and is defined using the fixed speed of light in vacuum.
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Length
Foot
The international foot is a unit of length defined as exactly 0.3048 meters and divided into 12 inches.
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Length
Mile
The international mile is a unit of length equal to exactly 1,609.344 meters or 5,280 feet.
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Volume
Liter
A liter is a unit of volume equal to one cubic decimeter, 1,000 milliliters, or 0.001 cubic meter.
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Volume
US Gallon
The US liquid gallon is a volume unit equal to exactly 231 cubic inches or 3.785411784 liters. It is smaller than the Imperial gallon.
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Temperature
Degree Celsius
Celsius is a temperature scale where 0 °C corresponds to 273.15 K and a change of 1 °C equals a change of 1 kelvin.
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Temperature
Degree Fahrenheit
Fahrenheit is a temperature scale where water freezes at 32 °F and boils at 212 °F at standard atmospheric pressure.
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Data
Byte
A byte is a unit of digital information conventionally made of eight bits. Storage prefixes may be decimal (KB) or binary (KiB).
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