A dosing device for dispensing a predetermined amount of liquid, in particular a predetermined amount of water, has a housing with a liquid inlet, a liquid outlet, and a flow channel therebetween. A valve element in the flow path can be opened and closed. A measuring device measures the flow rate through the flow channel in the direction of the liquid outlet. A controller has an operating unit or is coupled to an operating unit for signal transmission. The dosing device is actuatable by the operating unit. The controller is further coupled in terms of control technology to the valve element and to the measuring device, the controller holding the valve element in an open position or moving it to an open position when the dosing device is actuated.