The specific heat (or specific heat capacity) is the amount of heat required to increase the temperature of a unit amount of a substance by 1 kelvin. For example, the heat required to raise the temperature of 1 gram of water by 1 kelvin is 4.184 joules. The specific heat capacity is usually expressed as Jg-1K-1. It may also be expressed on a molar basis as Jmol-1K-1.
Specific heat capacities and heat capacities have the same symbols of and . The specific heat ratio, , has the same numeric value whether based on specific heats or heat capacities, since the respective amounts of substance cancel out.