Convert a temperature between Celsius, Fahrenheit and Kelvin. Enter the temperature and choose which scale it's given in, and the result is shown in the other two.
Celsius (°C) is the scale used every day across most of the world. It's set so that water's freezing point is 0 °C and boiling point is 100 °C at sea level. Fahrenheit (°F) is used mainly in the United States, and has a different zero point and a finer division. Kelvin (K) is the international SI unit for temperature and is used in scientific contexts, because the scale starts from absolute zero rather than the properties of water.
Absolute zero is 0 K, equivalent to −273.15 °C — the coldest temperature theoretically possible, where all thermal motion stops.
Absolute zero is the lowest temperature that can theoretically exist, defined as 0 Kelvin (−273.15 °C). At this temperature, particles have minimal thermal motion.
The Kelvin scale starts from an absolute zero point, which makes it practical for physical calculations where temperature enters directly into formulas, for example in gas laws and thermodynamics. The Celsius scale, by contrast, is based on the properties of water, which is not as fundamental in physics.
No, the Kelvin scale starts at absolute zero (0 K) and therefore cannot go negative under normal physical conditions. This is one of the reasons Kelvin is preferred in scientific calculations.