Three Phase Power Calculator
P = √3 × V_line × I_line × PF. Click any i for detail.
Circuit
Solve for
i
Mode
Power from volts, amps, and PF — or amps from watts. |
|
|---|---|
Line-line volts
i
Volts
Typical 208 or 480 V three-phase in buildings. |
|
Line amps
i
Amps
Used when solving for power. |
|
Watts
i
Watts
Real power, used when solving for current. |
|
Power factor
i
PF
Real power ÷ apparent power. Motors often 0.8–0.9 lagging. |
How to use this calculator
- Pick power or current.
- Enter line-line volts.
- Enter amps or watts.
- Set PF (1.0 if you want a resistive sketch).
Results explained
P = √3 × V × I × PF. kVA = √3 × V × I / 1000 (PF ignored). Single-phase watts-to-amps is the other converter.
Quick reference: three-phase
√3 ≈ 1.732.
| Item | Detail |
|---|---|
| 208 V × 10 A × 0.85 PF | See kW on the result |
| kVA vs kW | kW = kVA × PF |
| Single-phase | Watts to amps calculator |
| Voltage drop 3φ | Voltage drop calculator (3φ factor) |
Unbalanced legs and harmonics are not modeled.
How the estimate is built
P = √3 × V × I × PF. I = P / (√3 × V × PF).
Example scenario
208 V, 10 A, PF 0.85 → about 3.06 kW.
FAQ
Line-neutral volts?
This page wants line-line.
Horsepower of a motor?
Nameplate HP ≠ this kW without efficiency.
DC?
Use watts to amps with PF 1.