Impedance is measured in:

Impedance is measured in ohms ($\Omega$).

Impedance $Z$ is the total opposition to alternating current flow, combining resistance $R$ and reactance $X_L$ or $X_C$.

$$Z = R + j(X_L - X_C)$$

The SI unit of $R$, $X_L$, and $X_C$ is the ohm $\Omega$, so the unit of $Z$ is also the ohm $\Omega$.

Final answer: ohms ($\Omega$)

\Omega