Celsius (°C) is a metric unit of temperature measurement named after the Swedish astronomer Anders Celsius. It is defined as the temperature at which water freezes (0°C) and boils (100°C) at standard atmospheric pressure. Fahrenheit (°F) is a temperature unit used primarily in the United States and named after the German physicist Daniel Gabriel Fahrenheit. It is defined as the temperature at which a mixture of ice, water, and ammonium chloride freezes (-17.78°C) and the average human body temperature (98.6°F). Kelvin (K) is the base unit of temperature measurement in the International System of Units (SI). It is named after the British physicist William Thomson, 1st Baron Kelvin. Kelvin is defined as the temperature at which all molecular motion ceases (-273.15°C) and is commonly used in scientific and engineering applications. Enter temperature: Convert from: Celsius Fahrenheit Kelvin Convert to: Celsius Fahrenheit Kelvin Convert