Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Kelvin is the unit of temperature in the International System of Units (SI). It is based on absolute zero, where 0 Kelvin corresponds to the absence of thermal energy.
Related terms
Celsius: Celsius is another unit of temperature commonly used in everyday life. The boiling point of water at sea level is 100 degrees Celsius.
Fahrenheit: Fahrenheit is another unit of temperature mainly used in the United States. Water boils at 212 degrees Fahrenheit and freezes at 32 degrees Fahrenheit.
Absolute Temperature Scale: The absolute temperature scale starts from absolute zero (0 Kelvin) and measures temperatures relative to it, without negative values.