# density

> The density of the collider used to calculate its mass (when auto mass is enabled).

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.Physics2DModule

```csharp
public float density { get; set; }
```

### Remarks

When using [\_useAutoMass](/engine/6000.7/script-reference/unityengine/rigidbody2d/useautomass.md), increasing the collider density increases its mass - as does increasing its area - as the collider mass is calculated as a product of density and area.

Note that by default, [\_useAutoMass](/engine/6000.7/script-reference/unityengine/rigidbody2d/useautomass.md) is disabled, so the mass of the collider is set directly by [\_mass](/engine/6000.7/script-reference/unityengine/rigidbody2d/mass.md), and this density value is ignored.

Additional Resources: [\_mass](/engine/6000.7/script-reference/unityengine/rigidbody2d/mass.md), [\_useAutoMass](/engine/6000.7/script-reference/unityengine/rigidbody2d/useautomass.md)