Units & conversions

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 Temperature conversion formulas Celsius to Kelvin K = °C + 273.15 Kelvin to Celsius °C = K - 273.15 Celsius to Fahrenheit °F = 9/5 · (°C) +32 Fahrenheit to Celsius °C = 5/9 · (°F - 32) Fahrenheit to Kelvin K = 9/5 · (°F + 459.67) Fahrenheit to Kelvin °F = 5/9 · K - 459.67

The kelvin (K) is the unit of thermodynamic temperature. It is defined as the fraction 1/273.16 of the thermodynamic temperature of the triple point of water (TPW).

The triple point of a substance is the temperature and pressure at which three phases (gas, liquid, and solid) of that substance may coexist in thermodynamic equilibrium. The triple point of water (TPW) occurs at a temperature of 273.16 K.

The degree Celsius (°C) is the temperature unit of the International Temperature Scale of 1990 (ITS-90), adopted by the Comité international des poids et mesures (CIPM) in 1989. Historically, the scale was founded on the melting point of water, defined as 0 °C, and on the boiling point of water, defined as 100 °C, under normal atmospheric pressure (101325 Pa). Celsius remains a commonly adopted practical temperature scale. One kelvin is equal to one degree Celsius.

The degree Fahrenheit (°F) is the temperature unit widely used in the United States. On this scale the melting point of ice water is 32 °F and the boiling point is 212 °F. Back