What formula is used for DC circuits?

For DC circuits: P(kW) = I(A) × V(V) / 1000. Power equals current multiplied by voltage, then divided by 1000 to convert watts to kilowatts.

What formula is used for single-phase AC circuits?

For single-phase AC: P(kW) = I(A) × V(V) × PF / 1000. The power factor (PF) accounts for the phase difference between voltage and current.

What formula is used for three-phase AC circuits?

For three-phase AC: P(kW) = √3 × I(A) × V(V) × PF / 1000. The √3 factor (approximately 1.7321) accounts for the three-phase relationship. Voltage here is the line-to-line voltage.

What is the power factor?

The power factor (PF) is a number between 0 and 1 that represents the efficiency of AC power usage. Resistive loads (heaters, incandescent bulbs) have PF = 1. Motors and other inductive loads typically have PF between 0.7 and 0.95.

Why does DC not need a power factor?

DC circuits have no frequency and therefore no phase difference between voltage and current. Power factor is only relevant for AC circuits where reactive loads cause voltage and current to be out of phase.

What is the difference between kW and kVA?

kW (kilowatts) is real power — the actual work done. kVA (kilovolt-amperes) is apparent power. They are related by: kW = kVA × PF. For DC and purely resistive AC loads, kW equals kVA.

Amps to Kilowatts Calculator

Convert amperes (A) to kilowatts (kW) for DC, single-phase AC, or three-phase AC circuits instantly.

Circuit Parameters

Circuit Type

Current (A)

Voltage (V)

Power Factor (0 – 1)

Result

Enter values and press Calculate

Formula Reference

DC Circuits

kW = A × V / 1000

Single-Phase AC

kW = A × V × PF / 1000

Three-Phase AC

kW = √3 × A × V × PF / 1000

Result copied!

Summary

This calculator converts electric current measured in amperes (A) to power measured in kilowatts (kW). It supports three circuit types: DC circuits, single-phase AC circuits, and three-phase AC circuits, each using the correct electrical formula. Simply enter the current, voltage, and power factor (for AC circuits) to get an accurate kilowatt result.

How it works

Select your circuit type: DC, single-phase AC, or three-phase AC.
Enter the current in amperes (A).
Enter the voltage in volts (V).
For AC circuits, enter the power factor (between 0 and 1).
The calculator applies the correct formula and displays the result in kilowatts (kW).
Use the Reset button to start a new calculation.

Use cases

Calculate the power draw of electric motors and industrial equipment.
Size circuit breakers and wiring for residential or commercial installations.
Estimate generator or UPS capacity requirements.
Verify utility billing by converting measured current to kilowatts.
Design solar or battery storage systems based on load current.
Troubleshoot electrical panels and verify nameplate ratings.
Convert three-phase motor current to total power consumption.
Plan EV charging infrastructure based on charger current ratings.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu