Embodiments of the present invention provide for a foldable container adapted to measure a volume of liquid. The container comprises a box and a bag. The bag is preferably a substantially transparent plastic bag that lines an interior of the box. The box is convertible between a substantially flat configuration and a stable, volume-defining configuration. In one embodiment the box is a substantially transparent plastic box. In another embodiment the box is a paperboard or opaque plastic box having a window comprised of a substantially transparent material. One or more graduations are provided to indicate the volume of liquid in the container when the box is in the volume-defining configuration.