*Disclaimer*: use at your own risk.

This page helps calculate sound velocities using Christoffel equation. It can also be used to define the elastic properties of a material before calculating the free vibrations of a 3D object or an infinite cylinder.

This calculator computes the speeds of sound for a given propagation direction from the elastic constants and the mass density. The coordinates of the propagation direction must be expressed in the same spatial units: m, nm, Å, …

To choose a material, enter its mass density and elasticity tensor by clicking a pre-defined material or by entering your own values.

Two buttons allow to determine isotropic approximations:

- computes the closest isotropic material as in doi:10.2140/jomms.2006.1.223, equation 30
- computes the average of the largest and of the 2 lowest sound speeds for a large number of propagating directions