Electrical
Power Calculator
Calculate electrical power from current, voltage, power factor and efficiency.
Use this calculator for quick electrical load checks for single-phase and three-phase systems. Suitable for preliminary design checks, load assessments and comparing connected electrical demand.
Inputs
Result
Power
-
Enter values and click calculate.
Method
Single-phase power is calculated from:
P = V × I × PF × η
Three-phase power is calculated from:
P = √3 × V × I × PF × η
- P = power (W)
- V = voltage (V)
- I = current (A)
- PF = power factor
- η = efficiency
- Calculated power = -
Reference
- This calculator applies standard electrical power relationships between current, voltage and power.
- Three-phase calculations assume balanced load conditions.
- Typical UK nominal voltages are 230V for single-phase systems and 400V for three-phase systems.
- Relevant standards may include BS 7671 and associated electrical design guidance.
Design note: This calculator provides indicative results only. Final design should consider diversity, starting conditions, harmonics, equipment characteristics, circuit protection and installation method.