A measure of utilization for plant, or of the relationship between average and peak demand or supply, as determined by the formula: Average x 100 / Peak. For supply and demand calculations average and peak most often refer to daily demand within a year, but any other periods are possible. The resulting figure is usually expressed as a percentage but, where the period covered is a year, the percentage is sometimes multiplied by 8760, so that the load factor is expressed as a number of hours. Thus a 50% Load Factor can also be expressed as 4380 hours. See also Swing.