The overfill and fill line volumes are determined on twelve containers. Overfill is simply filling the container to a level equal to the top of the finish of the container. The typical methods for measuring fill line volume are: 1. Filling the container to a specific height and measuring the volume at that point. 2. Filling the container with a specific volume of water and measuring the height of the liquid and comparing it to the target height. The weight of the water at these two points is used to calculate the volume of the container by dividing the weight by the density of water at the recorded temperature.