A system for an electrophotographic image forming device includes a toner container having a reservoir for storing toner and an impact member configured to selectively impart an impulse force on the toner container to cause vibration of the toner container. A sensor is configured to sense the vibration of the toner container upon the impact member imparting the impulse force on the toner container. Processing circuitry in communication with the sensor is configured to determine an estimate of an amount of toner in the reservoir based on the sensed vibration of the toner container.