Several methods exist to measure the extent to which populations of all the districts in a plan vary, or differ collectively from the "ideal." The method expressed in the below table is "Overall Range."
Overall range is perhaps the most commonly used measure of population equality of all districts, which can be expressed as a percentage (relative) or the actual population numbers (absolute).
The "range" is a statement of the population deviations of the most populous district and the least populous district. For example, if the ideal district population is 100,000, the largest district in the plan has a population of 102,000, and the smallest district has a population of 99,000, then the range is +2,000 and -1,000, or +2% and -1%. The overall range is the difference in population between the largest and the smallest districts, expressed as a percentage or as the number of people. In the preceding example, the "overall range" is 3 percent or 3,000 people.