Disclosed is a toilet bowl water level gauge and associated methods. In one embodiment, the toilet bowl water level gauge comprises a gauge assembly having a stem with a float, and a sleeve, wherein the stem is inserted in the sleeve and slides through the sleeve. Also, the toilet bowl water level gauge comprises a support attached to the gauge assembly, the support being adapted to engage a rim of a toilet bowl. In addition, bowl level sensors are employed for automated calibration of an automated bowl fill system.