Formula & Calculator
Diversity Factor
Measures how much individual peak demands overlap, used in sizing shared electrical infrastructure.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| DivF | Diversity factor | dimensionless |
| ΣIndividual Max Demands | Sum of individual maximum demands | W (or VA) |
| System Max Demand | System maximum demand | W (or VA) |
What it means
The diversity factor is the ratio of the sum of individual maximum demands (of different loads) to the system maximum demand. DivF = Σ(Individual Max Demands) / System Max Demand. It is always ≥ 1 because loads do not peak simultaneously. A higher diversity factor means that the system can be smaller than the sum of individual peak demands, leading to cost savings. Example: Three loads have individual maximum demands of 400W, 500W, and 300W, summing to 1200W. However, the system maximum demand is 1000W. The diversity factor is 1200/1000 = 1.2. This is used to size the main service entrance and feeders.
Worked example
Diversity Factor – Practical Example
Real‑World| Parameter | Value |
|---|---|
| Σ individual max demands | 400 kW |
| System max demand | 300 kW |
| Formula | DivF = Σ / System |
Common mistakes
Watch for unit mismatches (W vs kW, single- vs three-phase) and remember to include power factor or efficiency where the formula requires it.Applications
Diversity factor DivF = Σ Individual Max Demands / System Max Demand accounts for the fact that not all loads peak simultaneously. It is used to size system capacity, especially in buildings and industrial plants. A higher diversity factor means more sharing of capacity. Engineers use it to optimise transformer and cable sizes, reducing costs and improving efficiency.
- Building and campus electrical design
- Transformer and feeder sizing with diversity
- System planning and peak demand analysis
- Cost optimisation of electrical infrastructure
- Educational understanding of load diversity