A variable power water heater is disclosed. In embodiments, the variable power water heater includes a water tank, a heating element, a power supply circuit, a switch, and a controller. The heating element may be disposed within or coupled to the water tank. The power supply circuit may be configured to generate a power signal for the heating element. The switch may be configured to couple the power supply circuit to the heating element, and the controller may be configured to toggle the switch according to a pulse width modulation (PWM) scheme to control a duty cycle of the power signal transmitted from the power supply circuit to the heating element.