A soap dispenser can be configured to dispense an amount of liquid soap, for example, upon detecting the presence of an object. Certain embodiments of the dispenser include a housing, reservoir, pump, motor, sensor, electronic processor, and nozzle. In certain embodiments, the sensor can be configured to generate a signal based on a distance between an object and the sensor. In certain embodiments, the electronic processor can be configured to receive the signal from the sensor and to determine a dispensation volume of the liquid. The dispensation volume can vary as a function of the distance between the object and the sensor. The processor can be configured to control the motor to dispense approximately the dispensation volume of the liquid.