Vacuum impedance of free space

vacuumImpedance is the characteristic impedance of electromagnetic waves in vacuum, expressed in ohms. It relates electric and magnetic field amplitudes of a freely propagating plane wave.

Use

It is useful in antenna, radiation, and field calculations. It is related to the electricConstant, magneticConstant, and speedOfLight.

Caveats

Vacuum impedance is not the resistance of a physical wire. Material wave impedance depends on the medium. Use divide only with compatible field units and distinguish impedance from conductanceQuantum.

Use Vacuum Impedance in a calculation

Enter vacuumImpedance on a calculator line to see its built-in value, or place the name inside a longer expression. Keep any displayed unit attached when converting or combining physical quantities, and check that every other value uses a compatible dimension.

The example above is editable, so you can replace surrounding values and test the constant in your own formula. Browse all constants to compare related values and notation.