There are four units of temperatures: Celsius, Fahrenheit, Kelvin and Rankine. The units of Kelvin and Rankine are the absolute temperatures that are very useful in calculations involving process systems.
However, for room temperatures, the common units used are Celsius and Fahrenheit. There is a derived equation relating Celsius and Fahrenheit. But for practical purposes where you don't have to memorize the equation, just remember that the boiling point of water is 100°C or 212°F. So, we use this relationship through ratio and proportion:
100°C/212°F = 158°C/x
x = (158*212)/100
x = 334.96°F
