It is impossible to convert watts to hertz, as the units measure different things. Watts measure how much power is being used, whereas hertz measure frequency – the amount of time required to complete a cycle. In alternating current, electricity reverses direction, and these cycles are measured in hertz.
The amount of time required for an alternating electric current to fulfill a cycle does not affect the amount of power that an appliance consumes. The power supply in the United States is rated at 60 hertz, which means that it takes one-sixtieth of a second for the current to complete a cycle.