Physics

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Latent Heat Calculator.

Calculate phase-change heat from mass and specific latent heat.

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Mass

Specific latent heat

Heat

0.000000J

Results update automatically as you type.

Use Cases

Physics homework and exam prep

Quickly verify calculations for phase change problems, ensuring correct use of mass and latent heat values.

Example: Calculate heat needed to melt 2 kg of ice (L = 334,000 J/kg).

Engineering and design calculations

Estimate energy requirements for processes involving melting, freezing, or vaporization in industrial or experimental setups.

Example: Determine heat required to vaporize 5 kg of water (L = 2,260,000 J/kg).

Frequently Asked Questions

What is specific latent heat?: Specific latent heat is the amount of heat energy required to change the phase of 1 kilogram of a substance without changing its temperature. It is measured in joules per kilogram (J/kg).
How do I use this latent heat calculator?: Enter the mass of the substance in kilograms and its specific latent heat in J/kg. The calculator multiplies them to give the total heat energy in joules (J).
Can this calculator be used for both melting and boiling?: Yes, the formula Q = m * L applies to any phase change, such as melting (fusion) or boiling (vaporization), as long as you use the appropriate specific latent heat value for that transition.

Tips & Common Mistakes

Tips

Ensure mass is in kilograms and specific latent heat is in J/kg to get the result in joules.
Use the correct latent heat value for the specific phase change (fusion vs. vaporization).
Remember that temperature remains constant during a phase change; this calculator only accounts for the energy of the phase transition.
For multi-step processes, calculate the sensible heat separately and add it to the latent heat.

Common Mistakes to Avoid

Using grams instead of kilograms for mass, leading to results off by a factor of 1000.
Confusing specific latent heat with specific heat capacity, which involves temperature change.
Forgetting to convert units if the latent heat is given in kJ/kg instead of J/kg.

Last updated: August 13, 2026

Use Cases

Physics homework and exam prep

Quickly verify calculations for phase change problems, ensuring correct use of mass and latent heat values.

Example: Calculate heat needed to melt 2 kg of ice (L = 334,000 J/kg).

Engineering and design calculations

Estimate energy requirements for processes involving melting, freezing, or vaporization in industrial or experimental setups.

Example: Determine heat required to vaporize 5 kg of water (L = 2,260,000 J/kg).

Frequently Asked Questions

What is specific latent heat?

Specific latent heat is the amount of heat energy required to change the phase of 1 kilogram of a substance without changing its temperature. It is measured in joules per kilogram (J/kg).

How do I use this latent heat calculator?

Enter the mass of the substance in kilograms and its specific latent heat in J/kg. The calculator multiplies them to give the total heat energy in joules (J).

Can this calculator be used for both melting and boiling?

Yes, the formula Q = m * L applies to any phase change, such as melting (fusion) or boiling (vaporization), as long as you use the appropriate specific latent heat value for that transition.

Tips & Common Mistakes

Tips

Ensure mass is in kilograms and specific latent heat is in J/kg to get the result in joules.
Use the correct latent heat value for the specific phase change (fusion vs. vaporization).
Remember that temperature remains constant during a phase change; this calculator only accounts for the energy of the phase transition.
For multi-step processes, calculate the sensible heat separately and add it to the latent heat.

Common Mistakes to Avoid

Using grams instead of kilograms for mass, leading to results off by a factor of 1000.
Confusing specific latent heat with specific heat capacity, which involves temperature change.
Forgetting to convert units if the latent heat is given in kJ/kg instead of J/kg.

Use Cases

Physics homework and exam prep

Quickly verify calculations for phase change problems, ensuring correct use of mass and latent heat values.

Example: Calculate heat needed to melt 2 kg of ice (L = 334,000 J/kg).

Engineering and design calculations

Estimate energy requirements for processes involving melting, freezing, or vaporization in industrial or experimental setups.

Example: Determine heat required to vaporize 5 kg of water (L = 2,260,000 J/kg).

Frequently Asked Questions

What is specific latent heat?

Specific latent heat is the amount of heat energy required to change the phase of 1 kilogram of a substance without changing its temperature. It is measured in joules per kilogram (J/kg).

How do I use this latent heat calculator?

Enter the mass of the substance in kilograms and its specific latent heat in J/kg. The calculator multiplies them to give the total heat energy in joules (J).

Can this calculator be used for both melting and boiling?

Yes, the formula Q = m * L applies to any phase change, such as melting (fusion) or boiling (vaporization), as long as you use the appropriate specific latent heat value for that transition.

Tips & Common Mistakes

Tips

Ensure mass is in kilograms and specific latent heat is in J/kg to get the result in joules.
Use the correct latent heat value for the specific phase change (fusion vs. vaporization).
Remember that temperature remains constant during a phase change; this calculator only accounts for the energy of the phase transition.
For multi-step processes, calculate the sensible heat separately and add it to the latent heat.

Common Mistakes to Avoid

Using grams instead of kilograms for mass, leading to results off by a factor of 1000.
Confusing specific latent heat with specific heat capacity, which involves temperature change.
Forgetting to convert units if the latent heat is given in kJ/kg instead of J/kg.