Calculation sequence
Step-by-step method
- Divide peak demand by connected load.
- Divide interval energy by interval duration.
- Divide average demand by peak demand.
ElectricalBeginnerEnergy and Demand
Demand Factor and Load Factor Calculator
Calculate demand factor, average demand, and load factor over a user-defined interval.
Why it matters: Connected load, peak demand, and average demand describe different aspects of facility use.
Calculated result
Engineering evaluation
Demand factor (DF)60 %
- Average demand (Pᵃᵛᵍ)
- 300 kW
- Load factor (LF)
- 50 %
Engineering interpretation
The entered period gives 60% demand factor, 300 kW average demand, and 50% load factor.
Important limitations
- Billing demand and utility ratchets may use different definitions.
Engineering knowledge center
Understand the calculation—not just the answer
Governing relationships
DF = 100Pᵈ/Pᶜ
Pᵃᵛᵍ = E/t
LF = 100Pᵃᵛᵍ/Pᵈ
Current substitution
DF = 100×600/1000 = 60%; Pᵃᵛᵍ = 216000/720 = 300 kW; LF = 50%.
Equation legend
Inputs and calculated quantities
- Pᶜ
- Connected load — kW
- Pᵈ
- Measured peak demand — kW
- E
- Interval energy — kWh
- t
- Interval duration — h
- DF
- Demand factor — %
- Pᵃᵛᵍ
- Average demand — kW
- LF
- Load factor — %
Applications
How this calculation is used
Building design
Screen entered load and demand relationships.
Construction
Check meter interval and connected-load boundaries.
Commissioning
Reconcile interval energy with peak and connected demand.
Quality controls
Assumptions and limitations
Assumptions
- Entered values describe one stable operating condition and use a consistent electrical or metering boundary.
- Measured quantities are simultaneous, representative, and obtained with appropriately rated instruments.
Limitations
- Does not determine billing demand or utility ratchets.
- Metering interval, coincident demand, and connected-load scope must be documented.
Field use
Verification procedure
- Follow the approved electrical-safety program and use correctly rated instruments.
- Confirm wiring, ratios, units, operating mode, and measurement boundaries.
- Document simultaneous readings and compare with approved project and manufacturer data.
Common engineering mistakes
- Combining values from different time intervals, phases, or measurement boundaries.
- Treating a screening result as equipment selection, protective-device coordination, or code compliance.
Technical basis
References and source standards
- U.S. Department of Energy—Energy Saver and Better BuildingsFederal energy-management, lighting, motor, and building-energy guidance.
- NIST Guide for the Use of the International System of UnitsElectrical quantity, unit, symbol, and conversion context.
Engineering calculation disclaimer
These engineering tools are provided for educational, preliminary evaluation, field verification, and commissioning support. Results depend on the accuracy of user-entered information and the assumptions stated for each calculation. Every colored status and comparison is a screening indicator only; project criteria, contract requirements, applicable codes, manufacturer instructions, measurement uncertainty, and authorized engineering judgment govern. The tools do not replace project-specific engineering analysis or the judgment of a licensed professional engineer.
Read the full use and limitation statement