Abstract: A volumetrically variable measuring dispenser cap comprising three primary components; an adaptor section attachable to a container having an inlet port, a volume selection ring rotatably mounted on the adaptor and having a closure plate of a size sufficient to cover the inlet port on the adaptor when appropriately rotated, and having a movable wall extending upward from the closure plate and finally, a rotatable chamber captively mounted to the volume selection ring having an inner cavity and a cover cap to close off the inner cavity. The device operates by movement of the selection ring so as to rotate the movable wall to a position within the inner cavity. The container to which the dispenser is attached is then inverted such that the material within the container falls through the inlet port in the adaptor, through the selection ring, and into the defined volumetric inner cavity.