Demand Factor Calculator — Maximum Demand,…

Connected load to coincident maximum-demand model

Turn connected electrical load into a transparent peak-demand estimate without confusing demand factor with load factor or diversity factor. Solve either the demand factor from measured maximum demand or the expected maximum demand from a project-specific factor.

How to use this calculator

Choose whether you are solving from a known demand factor or from a measured maximum demand.

Enter total connected real-power load in kW on a consistent boundary.

For an estimate, enter a project-specific demand factor from measured history, operating philosophy or an applicable design method; do not borrow an unrelated generic percentage.

Enter power factor and system voltage to add apparent-demand and current context.

Use the result as a planning input, then apply the governing electrical code, utility rules, duty/standby logic and engineering study before equipment selection.

Where people use it

•Convert a connected-load schedule into an expected maximum demand for early transformer or generator planning.
•Calculate demand factor from interval-meter maximum demand and known connected load.
•Compare peak demand with installed load after operational changes.
•Estimate kVA and feeder current from a real-power demand estimate.

Example: 500 kW connected load at 60% demand factor

Maximum demand = 500 × 0.60 = 300 kW. At 0.90 power factor that is 333.33 kVA. On a 415 V three-phase system the corresponding current is about 463.7 A.

Demand factor is a project input, not a universal code percentage

•Demand factor is maximum demand divided by connected load and should normally be between 0 and 1 for the same defined load boundary.
•Demand factor is not diversity factor. Diversity compares the sum of individual maxima with a coincident group maximum and is commonly greater than or equal to 1.
•Demand factor is not load factor. Load factor compares average load with maximum demand over a defined period.
•Do not invent a universal demand factor. Use interval data, operating philosophy, applicable code/utility methods or defensible project assumptions.
•Connected load and maximum demand must use the same real-power basis. If one value is kVA, convert consistently using an appropriate power factor before forming the ratio.
•The current result is a planning calculation, not an automatic conductor, breaker, transformer or generator selection.

Frequently asked questions

What is the electrical demand factor formula?+

Demand factor equals maximum demand divided by total connected load on the same load boundary and unit basis.

How do I calculate maximum demand from connected load?+

Multiply connected load by the chosen demand factor. For example, 500 kW at a 0.60 factor gives 300 kW maximum demand.

Can demand factor be greater than 1?+

Not for a consistently defined connected-load boundary. A value above 1 usually indicates mismatched units, boundaries, ratings or measurements and should be investigated.

What is the difference between demand factor and diversity factor?+

Demand factor compares one system maximum with its connected load. Diversity factor compares the sum of individual maximum demands with the coincident maximum of the combined group.

Is demand factor the same as load factor?+

No. Load factor is average load divided by maximum demand for a period; demand factor is maximum demand divided by connected load.

Should I use a typical demand factor to size equipment?+

A generic percentage is not a substitute for the governing code, utility requirements, measured interval data or a project load schedule. Use a defensible project-specific basis.

Semantic next steps

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