Single-Phase Power Calculator
Active, apparent and reactive power of a single-phase load from voltage, current and power factor.
Results
Active power
3496
W
Apparent power
3680
VA
Reactive power
1149.08
var
What this tool does
In an alternating-current circuit, the product of volts and amps is the apparent power in VA; only the part in phase with the voltage does useful work. The power factor is the fraction that does, which is why a 3680 VA load at 0.95 delivers 3496 W.
Formula
P = U × I × cos φ , S = U × I
Variables
| Symbol | Meaning | Unit |
|---|---|---|
u | Voltage | V |
i | Current | A |
pf | Power factor | — |
P | Active power | W |
S | Apparent power | VA |
Q | Reactive power | var |
Worked example
- Voltage230 V
- Current16 A
- Power factor0.95
- Active power3496 W
- Apparent power3680 VA
- Reactive power1149.08 var
Limitations
- Electrical installations are governed by national wiring rules. Cable sizing also depends on installation method, grouping, ambient temperature and protection devices, which this calculator does not evaluate.
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.