Convert Apparent Power (kVA) to Real Power (kW) instantly.
Resulting Real Power:
Understanding kVA and kW Conversion
In electrical engineering, distinguishing between kVA (kilovolt-amps) and kW (kilowatts) is crucial for sizing generators, UPS systems, and industrial equipment. While both measure power, they represent different aspects of electrical capacity.
The Difference: kVA vs. kW
kVA (Apparent Power): This is the total amount of power being used by a system. It includes both the working power and the "reactive" power used to maintain magnetic fields in motors or transformers.
kW (Real Power): This is the actual "working" power that performs the physical task, such as turning a motor shaft or heating a room.
Power Factor (PF): The ratio of real power to apparent power. In most industrial applications, a standard power factor of 0.8 is used as a baseline.
The kVA to kW Formula
To convert kVA to kW, you use the following mathematical formula:
kW = kVA × Power Factor
Conversion Chart (Standard 0.8 PF)
kVA Rating
kW at 0.8 PF
kW at 1.0 PF (Unity)
10 kVA
8 kW
10 kW
50 kVA
40 kW
50 kW
100 kVA
80 kW
100 kW
500 kVA
400 kW
500 kW
Why does Power Factor matter?
If your system is highly efficient with a power factor close to 1.0 (unity), your kVA and kW will be nearly identical. However, in systems with many inductive loads like motors and heavy machinery, the power factor drops, meaning you need more kVA capacity to deliver the same amount of kW output.
function calculateKvaToKw() {
var kva = document.getElementById("kvaInput").value;
var pf = document.getElementById("pfInput").value;
var resultDiv = document.getElementById("kvaResultContainer");
var output = document.getElementById("kwOutput");
var explanation = document.getElementById("calcExplanation");
if (kva === "" || isNaN(kva) || kva <= 0) {
alert("Please enter a valid positive kVA value.");
return;
}
if (pf === "" || isNaN(pf) || pf 1) {
alert("Power Factor must be between 0 and 1.");
return;
}
var kw = parseFloat(kva) * parseFloat(pf);
var roundedKw = kw.toFixed(2);
output.innerHTML = roundedKw + " kW";
explanation.innerHTML = kva + " kVA × " + pf + " PF = " + roundedKw + " kW";
resultDiv.style.display = "block";
resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}