How the Temperature Change Calculator Works
The Temperature Change Calculator calculates how much heat energy is required to raise or lower the temperature of a substance. It is based on the sensible heat equation:
where Q is heat energy, m is mass, c is specific heat capacity, and ΔT is the temperature change.
Heat Energy Formula
If the result is positive, heat is absorbed by the substance. If the result is negative, heat is released.
How to Use the Calculator
- Select whether you know the mass or the volume.
- Choose a substance or enter custom specific heat capacity and density values.
- Enter the temperature change ΔT.
- Click Calculate Heat Energy.
- Review the result in J, kJ, and MJ.
Specific Heat Capacity Values
The calculator uses approximate room-temperature values. Actual properties can vary with temperature, pressure, purity, and phase.
| Substance | c, J/kg°C | Density, kg/L |
|---|---|---|
| Water, liquid | 4184 | 1.000 |
| Ice | 2090 | 0.917 |
| Aluminum | 897 | 2.70 |
| Copper | 385 | 8.96 |
| Air | 1005 | 0.001225 |
| Argon | 520 | 0.001784 |
| Gold | 129 | 19.32 |
| Brass | 380 | 8.50 |
| Ethylene glycol | 2415 | 1.113 |
| Glycerol | 2410 | 1.26 |
Example Calculation
Suppose you want to heat 2 kg of water by 25°C.
m = 2 kg c = 4184 J/kg°C ΔT = 25°C
Then:
So the required heat energy is:
Mass vs Volume Input
If you know the mass, the calculation is direct. If you know the volume, the calculator first estimates mass using density:
The density input uses kg/L, so 1 liter of water has a mass of about 1 kg.
Assumptions and Limitations
- The calculator assumes no heat loss to the surroundings.
- It assumes the substance does not change phase.
- It assumes specific heat capacity stays approximately constant over the temperature range.
- For gases, pressure and process type can matter, so results are approximate.
Frequently Asked Questions
Can I use this for cooling?
Yes. Enter a negative temperature change if the substance cools down. A negative Q means heat is released.
Is °C the same as K for temperature change?
Yes. A temperature difference of 1°C is equal in size to a temperature difference of 1 K.
Why was the specific heat value corrected?
Specific heat capacity in this calculator is in J/kg°C. For example, water is about 4184 J/kg°C, not 4.18 J/kg°C.
Does this include heat loss?
No. Real systems usually lose heat to the surroundings, so engineering designs may need an efficiency or safety factor.