A drinking vessel for determining an amount of a liquid which is consumed and which includes a first portion, which has a base portion and a vertically, upwardly extending wall, and wherein the vertically upwardly extending wall defines an internal cavity, and the exterior-facing surface thereof defines a multiplicity of continuous, circumscribing, longitudinally spaced grooves; and a multiplicity of continuous, elastomeric members are individually received in the respective spaced grooves and which can be moved along the exterior-facing surface of the drinking vessel so as to permit a user to readily account for the amount of fluid they have consumed during a given time interval.