In a multi-head weigh filler (often called a combination weigh filler) product is dispensed to a container by combining the contents of multiple weigh hoppers. The control system computes the weight of product accumulating in each hopper and selects the combination of hoppers to provide the most accurate fill weight. The control system also optimizes the distribution of product through the radial troughs and pool hoppers. In this example three heads in an eight head machine combine to fill a single container. For simplicity the animation shows loading one weigh hopper only. The bars display the contribution of each hopper to the total fill weight.