A cap for use with a beverage container comprising a housing that attaches to a beverage container, the housing comprising an opening for dispensing the contents of the beverage container and further comprising a valve activated by a valve button. A sensor within the housing estimates the amount of a fluid that has been dispensed from the opening and a display device is provided for displaying the amount of fluid that has been dispensed from the opening. The display device may be any type of display, including an LED display, and LCD display, or a plurality of indicator lights.