Abdullah Shoaib
Managing Director
4 min read
Last Updated June 13, 2025
What is kVA?
Understanding kVA is essential for anyone involved in managing or purchasing electrical equipment for a business – especially if you’re dealing with generators, transformers or large electrical systems.
Below, we break down the definition of kVA, what it means for your business and how it differs from kW.
What is kVA in electricity?
Before we get into the details of what kVA means for you and your business, first let’s understand what the word itself means.
kVA is a unit of measurement used in electrical contexts, and it stands for kilovolt-amperes.
kVA measures apparent power in an electrical system, made up of reactive power (lost to inefficiencies) and real power (used to perform work). It reflects the total power supplied by a source, and the unit is commonly used to size generators and transformers. Match your power needs to the right sized transformer or generator, and your system will run more efficiently.
Understanding kVA is vital for business owners and employees because it helps to ensure that your electrical systems are safe, efficient and properly sized for your business needs. Having a good understanding of kVA can reduce your costs by:
- Dictating size: Making it easier for you to choose the right size of essential equipment like transformers and generators. Going too small risks overloads and failures, while oversizing can lead to unnecessary costs.
- Providing efficiency insights: Calculating the necessary kVA for your system load can help you to find the most efficient set-up for your business’s needs. This means you can make small changes to improve efficiency and save energy, supporting both the planet and your wallet.
- Lowering some energy bills: Some utility providers charge commercial customers based on kVA demand, not just kWh usage. If this applies to your business, reducing your kVA demand can lower energy bills.
- Improving system reliability: Getting the right set-up sorted helps to prevent system failures, overloads, voltage drops and equipment damage. All of this helps to prevent delays in order fulfilment, keeping your customers happier for longer.
In short, understanding kVA helps you choose the right equipment, reduce costs and maintain system performance and safety.
What is the difference between kVA and kW?
kVA (kilovolt-amperes) and kW (kilowatts) both measure power, but they represent different types of power in an electrical system.
kW refers to real power – in other words, the actual power that does useful work, such as running machines, lighting or heating. It’s the power your equipment uses to operate and what you’re typically billed for by your energy supplier.
On the other hand, kVA measures apparent power – the total power supplied to a system. This covers both real power (kW) and reactive power, which doesn’t perform useful work but is necessary to maintain electric and magnetic fields in certain equipment like motors and transformers.
The key factor that links them is power factor (PF), a number between 0 and 1 that indicates how efficiently power is being used:
kW = kVA × Power Factor
For example, if your power factor is 0.8 and your equipment requires 100 kW of real power, your system will draw 125 kVA of apparent power.
Another way to look at it is to think of it as a loaf of bread. kVA is represented by the loaf of bread as a whole. But whenever you slice bread, you always lose some of it as crumbs. kW is represented by the slices you eat – the loaf as a whole, minus wastage.
Understanding the difference helps businesses size electrical equipment correctly, avoid overloading systems and improve energy efficiency for all your commercial electricity needs. While kW reflects energy usage, kVA shows the demand placed on your electrical infrastructure. So, when buying a transformer or generator, you need to make sure it’s rated to handle both the maximum kW and kVA your system requires.