Calor latente Q=mL
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
This latent heat calculator uses the formula Q = m * L to determine the amount of thermal energy required to change the physical state of a substance, such as fusion (solid to liquid) or vaporization (liquid to gas), without changing its temperature. The latent heat of fusion (Lf) and vaporization (Lv) are tabulated values for each material, and the calculator allows you to select the substance and mass to obtain the required heat in joules.
The operation is simple: enter the mass of the substance in grams and choose between fusion or vaporization. The calculator applies the corresponding L value (for example, for water, Lf = 334 J/g and Lv = 2260 J/g) and returns Q in joules. This is useful in physics, chemistry, or engineering problems, such as calculating the energy to melt ice or boil water.
Use this tool in educational contexts, heating/cooling projects, or when sizing thermal systems. Remember that latent heat does not depend on temperature, only on mass and substance. Caution: ensure you use the correct mass unit (grams) and check that the L value is in the same unit (J/g).
Frequently asked questions
What is latent heat?
It is the energy required to change the physical state of a substance without changing its temperature, such as melting ice or evaporating water.
What is the difference between latent heat of fusion and vaporization?
Latent heat of fusion is for solid to liquid change, while vaporization is for liquid to gas. The values differ for each substance.
Can I use this calculator for any substance?
The calculator includes common substances like water, ice, alcohol, and mercury. For others, consult a table of latent heats.
Does the calculator consider temperature?
No, latent heat is independent of temperature. The energy calculated is only for the phase change at a constant temperature (melting or boiling point).
Why is the result in joules?
The joule is the standard SI unit of energy. To convert to calories, multiply by 0.239.