Result and graph appear here
Submit the form to calculate total heat, stepwise phase transitions, export files, and plot cumulative energy against temperature.
Enter calculation data
Use a preset for faster entry, or overwrite any property for a custom material.
Example data table
These sample rows illustrate typical workflows. Replace them with your own measured values when accuracy matters.
| Material | Mass | Initial Temp | Final Temp | Melting Point | Boiling Point | Total Heat |
|---|---|---|---|---|---|---|
| Water / Ice / Steam | 2.00 kg | -20 °C | 120 °C | 0 °C | 100 °C | 6,180.300 kJ |
| Ethanol | 1.50 kg | -130 °C | 90 °C | -114.1 °C | 78.37 °C | 2,198.472 kJ |
| Paraffin Wax | 3.00 kg | 15 °C | 120 °C | 60 °C | 370 °C | 1,405.500 kJ |
Formula used
The calculator combines sensible heating or cooling and latent phase change energy in a piecewise energy balance.
Sensible heat within one phase
Qsensible = m × cp × ΔT
Here, m is mass, cp is the specific heat for the active phase, and ΔT is the temperature change.
Latent heat at a phase boundary
Qlatent = m × L
L is the latent heat of fusion or vaporization. Heating makes it positive. Cooling makes it negative.
Total heat: The page adds every sensible segment and every latent segment across the entered path, so Qtotal = ΣQsensible + ΣQlatent.
How to use this calculator
- Choose a preset or enter custom thermal properties.
- Enter mass and select the mass unit.
- Select your temperature scale, then enter initial and final temperatures.
- Provide melting and boiling points for the chosen material.
- Enter specific heats for solid, liquid, and vapor regions.
- Enter latent heat of fusion and vaporization.
- Adjust decimal precision and submit the form.
- Review totals, stepwise energy changes, and the cumulative Plotly graph.
- Download the result summary as CSV or PDF if needed.
Frequently asked questions
1) What does this calculator estimate?
It estimates total heat added or removed when a material moves through solid, liquid, and vapor regions, including melting, freezing, boiling, and condensation steps.
2) Why are there separate specific heat inputs?
Thermal storage changes by phase. Solids, liquids, and vapors usually respond differently to temperature change, so the calculator applies a different heat capacity in each region.
3) When should I use the boundary phase selector?
Use it when the initial temperature exactly matches the melting or boiling point. It tells the model which side of the transition the material occupies before energy is applied.
4) Are the preset values exact?
No. Presets are convenient starting points. For design work, replace them with values from your material specification, property database, operating pressure, and temperature range.
5) Does pressure affect the answer?
Yes. Pressure can shift phase transition temperatures and latent heats. This version handles pressure indirectly through the values you enter for melting point, boiling point, and thermal properties.
6) Why can the total heat be negative?
A negative result means heat leaves the material. That happens during cooling, condensation, or freezing when the final state contains less internal energy than the initial state.
7) What does the graph show?
The graph plots cumulative heat against temperature. Sloped sections show sensible heating or cooling. Vertical jumps at fixed temperature show latent phase change energy.
8) Can I use this for engineering studies?
Yes, for preliminary estimates, teaching, and screening. For detailed design, verify pressure dependence, variable heat capacity, mixture behavior, and measured transition data.