Temperature is a measure of the ability of any physical system to transfer heat energy to another system. The temperature of a substance is related to the average kinetic energy of its molecules.
The basic thermometer contains a liquid that expands at a predictable rate as the temperature increases. The glass bulb thermometer was invented by German physicist Daniel Gabriel Fahrenheit in 1709. There are various standardized numerical measures of temperature. Use the following calculator to convert a temperature value into Kelvin, Fahrenheit, Celsius, Rankine and Reaumur scales.