Three Phase Power Calculator
Calculate three phase power step by step: P = √3 × V_LL × I_L × PF; S = √3 × V_LL × I_L.
In short
Formula: P = √3 × V_LL × I_L × PF; S = √3 × V_LL × I_L.
Real power
11.7779 kW
- Apparent power
- 13.8564 kVA
- Reactive power
- 7.2993 kvar
- Watts
- 11,777.9455 W
What this calculator does
Calculate three phase power step by step: P = √3 × V_LL × I_L × PF; S = √3 × V_LL × I_L. Worked example, questions and limitations included.
Use it to turn Line-to-line voltage, Line current, Power factor into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this electrical calculation.
Inputs and what they mean
- Line-to-line voltage
- — number value.
- Line current
- — number value.
- Power factor
- — number value.
How to use it
- Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
- Check the breakdown to see every intermediate step.
- Read the limitations before relying on the result.
Formula
Uses line-to-line voltage and line current for a balanced load.
Power factor between 0 and 1.
For phase-to-neutral voltage, P = 3 × V_LN × I × PF (equivalent).
P = √3 × V_LL × I_L × PF; S = √3 × V_LL × I_L.
Inputs used: Line-to-line voltage, Line current, Power factor.
Worked example
400 V, 20 A, PF 0.85
- S = 1.732 × 400 × 20 = 13,856 VA.
- P = 13,856 × 0.85 = 11,778 W ≈ 11.78 kW.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Balanced load only.
- Sinusoidal waveforms assumed.
- Motor efficiency not included.
- Results are estimates for planning and learning. Real designs, installations and bids must be checked by a qualified, licensed professional against the codes that apply where you work.
- The result depends on the values you enter for this three phase power calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Common questions
Where does √3 come from?
In a balanced three-phase system, line voltage is √3 times phase voltage, so total power is √3 × V_LL × I rather than 3 × V × I. Check the formula, example, and limitations on this page before using the result for a real electrical decision.
What if my load is unbalanced?
Calculate each phase separately (V_LN × I × PF) and add them; this calculator assumes balance. Check the formula, example, and limitations on this page before using the result for a real electrical decision.
Is this motor output power?
No, it is electrical input. Multiply by motor efficiency for shaft power.
How do I use the Three Phase Power Calculator?
Enter the required values for Line-to-line voltage, Line current, Power factor. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Three Phase Power Calculator use?
P = √3 × V_LL × I_L × PF; S = √3 × V_LL × I_L. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the Three Phase Power Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Related tools
Calculate electrical power step by step: P = V × I = I² × R = V² ÷ R (DC or resistive AC using RMS values).
Calculate voltage divider step by step: Vout = Vin × R2 ÷ (R1 + R2).
Calculate resistance step by step: R = V ÷ I, or for a conductor R = ρ × L ÷ A (A in m²).