Electrical Power & Current Calculator

Power / Current Converter

Results for guidance only. Verify against current standards and manufacturer data.
Not a substitute for engineering judgement or a licensed professional.

Methodology

For three-phase AC circuits, current is calculated as $I = \frac{P \times 1000}{\sqrt{3}\,V\,\mathrm{PF}}$, where P is active power in kW, V is line-to-line voltage, and PF is power factor. Single-phase circuits omit the $\sqrt{3}$ factor. DC circuits use the simple relationship $P = V\,I$ with no power factor consideration. When horsepower is entered, it is first converted to kW (1 HP = 0.7457 kW) and divided by motor efficiency to obtain electrical input power, since HP represents mechanical output.

Worked Example

A 15kW three-phase load at 415V with a power factor of 0.85: $I = \frac{15 \times 1000}{\sqrt{3}\times415\times0.85} = 24.6\ \mathrm{A}$. The apparent power is 15 / 0.85 = 17.6 kVA.

Assumptions & Limitations

• Assumes balanced three-phase loading across all phases
• Power factor is user-specified — verify against nameplate or measured data where available
• Does not account for harmonic distortion or non-linear loads
• HP conversion assumes standard 0.7457 kW/HP mechanical conversion factor