Enthalpy Calculator

Enthalpy is a measure of the total heat content of a thermodynamic system. In practical terms, the enthalpy change of a process tells you how much heat energy is absorbed from or released to the surroundings. For processes that involve a change in temperature without a change in phase, the enthalpy change is calculated using the formula Q equals m times c times delta T, where m is the mass in kilograms, c is the specific heat capacity of the substance in joules per kilogram per kelvin, and delta T is the temperature change in degrees Celsius or kelvin (the magnitude is the same for either unit). A positive result means the process is endothermic: the substance absorbs heat, and its surroundings cool down. A negative result means the process is exothermic: the substance releases heat to its surroundings. Water has an unusually high specific heat capacity of about 4184 J/kg/K, which is why it takes a long time to heat or cool compared with metals and most other materials. This calculator covers sensible heat changes. It does not cover phase changes (for those, use the Latent Heat Calculator) or chemical reaction enthalpies calculated from bond energies or Hess cycles. Enter the mass, the specific heat capacity (common material presets are provided), and the temperature change, and the tool returns the enthalpy change in joules and kilojoules along with the direction of heat flow.

This calculator covers sensible heat (temperature change) only. For energy in phase changes, use the Latent Heat Calculator.