The power rating of a diode is defined as the maximum value of power that can be dissipated without failure if V f is the forward biased voltage and I f is the forward biased current.

Pd= V f x I f.

The power rating of a diode is defined as the maximum value of power that can be dissipated without failure if V f is the forward biased voltage and I f is the forward biased current.

Pd= V f x I f.