# Curie’s Law Calculator

URL: https://speedycalculator.com/calculators/physics/curies-law/
Last updated: 2026-10-30

> The Curie's law calculator finds the magnetisation and magnetic susceptibility of a paramagnetic material from its Curie constant, the applied magnetic field and the temperature.

## Inputs

- Curie constant C (K·A/(T·m))
- Magnetic field B (T, mT, µT, G, nT)
- Temperature T (K, °C, °F)

## Results

- Magnetisation M
- Magnetic susceptibility χ

## Formula

```
M = C·B/T,  χ = μ₀·C/T
```

## Explanation

Paramagnets become magnetised in a field, but thermal motion fights the alignment. Pierre Curie found that the magnetisation is inversely proportional to temperature – the basis of magnetic thermometers at very low temperatures.

### How to use the Curie's Law Calculator

- **Curie constant C (K·A/(T·m))**
- **Magnetic field B**
- **Temperature T**

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Enter the Curie constant, magnetic field and temperature.

### Tips

- Use absolute temperature (K) in gas laws and efficiency formulas.
- Temperature differences are the same in K and °C.
- Heat = mass × specific heat × temperature change when no phase change occurs.
- Phase changes need latent heat at a constant temperature.

### Common mistakes to avoid

- Using °C in pV = nRT.
- Forgetting latent heat during melting or boiling.
- Confusing heat capacity (J/K) with specific heat (J/(kg·K)).

### Inputs explained

FieldWhat to enterCurie constant C (K·A/(T·m))A numberMagnetic field BUnits: T, mT, µT, G, nTTemperature TUnits: K, °C, °F

### What each result means

- **Magnetisation M** = [Curie constant C (K·A÷(T·m))]×[Magnetic field B]÷[Temperature T]
- **Magnetic susceptibility χ** = 1.25663706212e-6×[Curie constant C (K·A÷(T·m))]÷[Temperature T]

### Example values

How the main result changes when **Curie constant C** changes and everything else stays at the example values above:

Curie constant C (K·A/(T·m))Magnetisation M (A/m)0.50.1250.750.187510.251.250.31251.50.37520.5

## Worked example

Inputs — Curie constant C (K·A/(T·m)): 1; Magnetic field B: 1 T; Temperature T: 4 K.

Results — **Magnetisation M = 0.25 A/m**; Magnetic susceptibility χ = 3.1416e-7.

## Key terms

- **Paramagnetism**: Weak attraction to magnetic fields from unpaired spins.

## FAQ

**When does Curie's law hold?**
For paramagnets at high temperatures and weak fields.

**What happens at low temperature and strong field?**
Magnetisation saturates.

**What is the Curie–Weiss law?**
A modification for materials that order magnetically.

**Where is it used?**
Low-temperature thermometry and magnetic cooling.

**What formula does the Curie's Law Calculator use?**
M = C·B/T,  χ = μ₀·C/T.


## Sources

- [OpenStax – University Physics Volume 2](https://openstax.org/details/books/university-physics-volume-2)
- [HyperPhysics (Georgia State University)](http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html)