Using CalcuGo's heat capacity calculator, you can determine the capability of a body to absorb heat. Not sure what heat capacity is, or how it is different from specific heat? Worry not — we have got you covered. Read on to learn the definition, units, and formula for heat capacity (also known as thermal capacity). We have also included a section on heat capacity vs. specific heat.
What is heat capacity?
The heat capacity (or thermal capacity) of a body is the amount of heat required to raise the body's temperature through a unit degree. This quantity tells us how much heat we should supply to heat a cup of water or a bucket of water: since both hold a different volume and hence have a different mass of water, they need a different amount of heat.
From the heat transfer equation, we know that the amount of heat (∆Q) required to raise the temperature of a body of mass m by ∆T is:
∆Q = c · m · ∆T
where c is the specific heat of the body. If you don't remember its definition, visit our specific heat calculator.
Rearranging the heat transfer equation, we can get the formula for heat capacity S:
S = ∆Q / ∆T = c · m
Here, we note that the heat capacity depends on the body's mass and its specific heat capacity.
The SI unit of heat capacity is J/K (joules per kelvin). Another commonly used unit of heat capacity is cal/°C. Notice that this equivalence is possible only because we are dealing with temperature differences. For US customary units, heat capacity is measured in BTU/°F.
How to calculate the heat capacity of an object
Let us see how to calculate the heat capacity of any object using CalcuGo's heat capacity calculator. We will calculate the heat capacity of a cup of water (236 g = 0.236 kg). The specific heat of water is about 4 186 J/(kg·K) (4.186 J/(g·°C)).
- Pick your unit system — metric (SI) or US customary (imperial).
- Enter the water's mass, i.e., 0.236 kg.
- Using the drop-down menu, choose the substance, and the specific heat capacity field will display the corresponding value. If you already know the specific heat capacity for water, input its value, i.e., 4 186 J/(kg·K).
- As a result, you can see the calculated heat capacity, i.e., about 987.4 J/K. It means that we need to supply 987.4 J of energy to raise the water temperature in the cup by 1 °C.
Additionally, you can choose different unit systems for heat capacity, specific heat, and mass. Optionally enter a temperature change (∆T) to find the heat ∆Q that must be supplied or removed, and an energy price (in US dollars, Russian rubles, or 10 more world currencies) to estimate the running cost.
How about estimating the heat capacity of a bucket of water and comparing it with that of a cup of water? Just increase the mass and watch the heat capacity grow proportionally.
If you want to calculate the heat energy absorbed or released during a phase transition, we recommend checking our latent heat calculator.
Heat capacity vs. specific heat
These two quantities are closely related but not the same:
- Specific heat (c) is an intensive property — it does not depend on how much of the substance you have. It is measured per unit of mass, e.g., J/(kg·K) or BTU/(lb·°F).
- Heat capacity (S) is an extensive property — it describes a particular object and depends on its mass. It is measured in J/K, cal/°C, or BTU/°F.
The relationship between them is simply S = c · m. A large bucket of water has the same specific heat as a small cup of water, but a much larger heat capacity, because it contains far more mass.
Typical specific heat values
| Material | J/(kg·K) | BTU/(lb·°F) |
|---|---|---|
| Water (liquid) | 4 186 | 1.000 |
| Ice | 2 090 | 0.499 |
| Ethanol | 2 440 | 0.583 |
| Air (dry) | 1 005 | 0.240 |
| Aluminum | 897 | 0.214 |
| Glass | 840 | 0.201 |
| Iron / Steel | 449 | 0.107 |
| Copper | 385 | 0.092 |
| Gold | 129 | 0.031 |
| Lead | 128 | 0.031 |
FAQs
- What is the heat capacity of water?
- It depends on how much water you have. For 1 kg of water, the heat capacity is 4 186 J/K, since water's specific heat is 4 186 J/(kg·K) and S = c · m. For a 0.236 kg cup, it is about 987.4 J/K.
- What is the difference between heat capacity and specific heat?
- Specific heat is per unit mass and does not depend on the amount of substance (intensive). Heat capacity describes a specific object and scales with its mass (extensive). They are linked by S = c · m.
- What are the units of heat capacity?
- The SI unit is joules per kelvin (J/K). It can also be expressed in cal/°C (1 cal = 4.184 J) or, in US customary units, BTU/°F.
- How do I find the heat needed to change an object's temperature?
- Multiply the heat capacity by the temperature change: ∆Q = S · ∆T. For example, raising a cup of water (S ≈ 987.4 J/K) by 1 °C requires about 987.4 J.
- Can heat capacity be negative?
- For ordinary objects, no. Mass and specific heat are positive, so S = c · m is positive. A negative ∆Q simply means heat is being removed (the object is cooling), but the heat capacity itself stays positive.