The formula for specific latent heat is the amount of energy released or formed divided by the mass. The formula is notated as L = Q/m, where L is the latent heat, Q is the change in energy in terms of heat, and m is the substance's mass.
The latent heat is typically expressed either in terms of joules or of British thermal units. The formula for the specific latent heat can also be used to find the latent heat of fusion and the latent heat of vaporization. The amount of energy represented as Q in the latent heat formula can be found from the specific heat capacity, the mass and the change in temperature.