🌌 Alfven Velocity Calculator
Enter the magnetic field strength and plasma mass density to calculate the Alfven velocity, the speed at which magnetic disturbances propagate through a plasma.
What is Alfven velocity?
The Alfven velocity is the speed at which magnetohydrodynamic (MHD) waves travel through a magnetized plasma, analogous to how sound waves travel through air. It’s a key quantity in space physics, fusion research, and astrophysics.
The formula
Alfven velocity is calculated as VA = B ÷ √(μ0 × ρ), where B is the magnetic field strength in Tesla, ρ is the plasma mass density in kg/m3, and μ0 is the permeability of free space (4π × 10-7 T·m/A).
This formula assumes an ideal, non-relativistic, collisionless plasma. In very low-density or high-field environments the calculated value can approach or exceed the speed of light, at which point relativistic corrections become necessary. This calculator is for general educational reference.