Load Diversity Factor Calculator
Diversity Factor = Sum of individual maximum demands / Maximum demand of the group.
Introduction
The load diversity factor calculator helps estimate how much coincidence exists between a group of connected loads. In electrical design, not every connected load reaches its maximum at the same time, so engineers use diversity factor to avoid oversizing feeders, transformers, panels, and backup systems. This is a valuable planning concept in buildings, campuses, industrial sites, apartment projects, and mixed-use facilities.
A higher diversity factor means the sum of individual maximum demands is much larger than the actual maximum demand seen by the combined system. That usually allows a more economical design without assuming that every load is on at full value at the same moment.
This is particularly useful in feeder and transformer planning, where realistic diversity assumptions can reduce oversizing while still supporting safe and reliable operation.
Formula
Diversity Factor = Sum of individual maximum demands / Maximum demand of the system
Variable Definitions
Individual maximum demands = peak demand values of each separate load
System maximum demand = measured or estimated peak demand of the combined group
Diversity factor = ratio used to compare the two
Units
The calculator can use amperes, kilowatts, or another demand unit, but every value must use the same unit. If the individual values are entered in amperes, the system maximum must also be in amperes. If the loads are in kilowatts, the system maximum must also be in kilowatts.
Worked Example 1
Suppose four loads have maximum demands of 10 A, 15 A, 5 A, and 8 A.
Sum of individual maximum demands = 38 A
If the measured group maximum demand is 30 A:
Diversity factor = 38 / 30 = 1.27
This indicates the combined demand peaks lower than the simple sum of all individual peaks.
Worked Example 2
Consider three commercial loads with individual maximum demands of 20 kW, 12 kW, and 9 kW.
Sum of individual demands = 41 kW
If the building peak demand is 28 kW:
Diversity factor = 41 / 28 = 1.46
This suggests a useful amount of non-coincident loading across the building.
Practical Notes
Diversity factor is different from demand factor and load factor. Diversity factor compares multiple peak loads, while load factor relates average load to peak load over time. Use this calculator when grouping loads for feeder sizing, transformer sizing, and distribution planning, but remember that the final design still depends on code rules, site measurements, and engineering judgment.