Our kW to kVA calculator lets you quickly find apparent power from real power and power factor. Enter the load in kilowatts (kW), add the power factor (PF), and the calculator gives you the corresponding kVA value.
The basic formula is:
kVA = kW ÷ PF
If you already know the kW and PF, the calculation takes only a few seconds. The part that needs more attention is choosing the right load value and the right power factor, especially when you're working with generators, transformers, or industrial equipment.
This guide covers the formula, practical conversion examples, connected load vs running load, and real-world considerations from industrial electrical work.
How to Convert kW to kVA
To convert kW to kVA, you need:
- Real power: kW
- Power factor: PF
- Apparent power: kVA
Use this formula:
kVA = kW ÷ PF
Here:
- kW represents real or active power.
- kVA is the term applied to a system's apparent power.
- PF stands for power factor, the third value in this relationship.
Since power factor is essentially real power divided by apparent power, you can flip the formula around as PF = kW ÷ kVA.
Worked Example
Take a machine drawing 100 kW at a power factor of 0.8.
kVA = 100 ÷ 0.8
kVA = 125 kVA
The load therefore has an apparent power of 125 kVA at that operating condition.
Use our kVA to kW Calculator for instant and accurate results.
Getting Familiar with kW
A kilowatt (kW) measures real, usable power.
It represents the power associated with useful work in an electrical system. Motors use real power to produce mechanical output, while heaters use it to produce heat.
You'll generally spot kW on an equipment's nameplate or in electrical readouts, since it reflects the load's working power.
Understanding kVA
kVA, short for kilovolt-ampere, is the unit used to measure apparent power.
In an AC system, apparent power is related to the voltage and current supplied to the load. It accounts for the total electrical loading rather than only the real-power portion.
For this reason, generators and transformers are commonly specified in kVA. Manufacturer specifications for generators and transformers show capacity ratings in kVA.
A simple way to remember the three terms:
- kW → real power
- kVA → apparent power
- PF → relationship between real and apparent power
Why Does Power Factor Matter?
Real power and apparent power are tied together through the power factor.
The formula is:
PF = kW ÷ kVA
Rearranging it gives:
kVA = kW ÷ PF
A PF close to 1 gives a kVA value close to the kW value. A lower PF produces a higher kVA requirement for the same kW. (Fluke)
Compare a 100 kW Load
| Real Power | Power Factor | Apparent Power |
|---|---|---|
| 100 kW | 1.00 | 100 kVA |
| 100 kW | 0.95 | 105.26 kVA |
| 100 kW | 0.90 | 111.11 kVA |
| 100 kW | 0.85 | 117.65 kVA |
| 100 kW | 0.80 | 125 kVA |
The kW hasn't changed. kVA shifts here simply because PF is different — kW stays constant.
Get instant and accurate results with our kW to Amps Calculator.
kW to kVA Calculator Examples
#1. 10 kW at 0.8 PF
kVA = 10 ÷ 0.8 = 12.5 kVA
#2. 25 kW at 0.9 PF
kVA = 25 ÷ 0.9 = 27.78 kVA
#3. 50 kW at 0.85 PF
kVA = 50 ÷ 0.85 = 58.82 kVA
#4. 100 kW at 0.95 PF
kVA = 100 ÷ 0.95 = 105.26 kVA
#5. 500 kW at 0.8 PF
kVA = 500 ÷ 0.8 = 625 kVA
The arithmetic is simple. Once the math is done, the actual engineering decisions begin.
So What Does a 0.8 Power Factor Actually Mean?
With a PF of 0.8, only 80% of the apparent power is being used as real power.
For a 100 kW load:
100 ÷ 0.8 = 125 kVA
A 0.8 PF value is also commonly encountered in generator specifications, but it shouldn't be treated as the PF of every electrical load. Generator manufacturers can provide ratings and test information at different PF conditions. For example, Caterpillar publishes generator specifications with test reports at both 0.8 and 1.0 PF.
For an actual installation, use the equipment data or measured PF whenever it's available.
Connected Load vs Running Load
This is one area where I see confusion regularly in industrial electrical work.
#2. Connected Load
Connected load is the combined rated capacity of the equipment connected to the electrical system.
Suppose a factory has:
| Equipment | Connected Load |
|---|---|
| CNC machines | 300 kW |
| Air compressors | 150 kW |
| HVAC | 120 kW |
| Industrial heaters | 200 kW |
| Pumps | 150 kW |
| Lighting and auxiliaries | 80 kW |
| Total | 1,000 kW |
The plant has a 1,000 kW connected load.
#2. Running Load
Running load is the power being consumed by equipment that is operating at a particular time.
The same factory might be running at:
- CNC machines: 220 kW
- Compressors: 80 kW
- HVAC: 90 kW
- Pumps: 70 kW
- Lighting and auxiliaries: 60 kW
Running load = 520 kW
So the plant can have:
Connected load = 1,000 kW
Running load = 520 kW
These values serve different purposes. For generator or transformer selection, don't blindly use either number. The load profile, maximum demand, starting requirements, future expansion, and operating pattern also need to be reviewed.
Find amps from Amps in seconds with our accurate Amps to Kilowatts Calculator.
Real Industrial Example: 1,000 kW Connected Load
Here's a practical example from industrial work.
In one project, the plant had an approximate 1,000 kW connected load. The plant had power factor correction capacitor banks installed, which brought the measured power factor to 0.989.
The apparent power was:
kVA = 1,000 ÷ 0.989
kVA = 1,011.12 kVA
So the calculated apparent power was approximately 1,011 kVA.
For this project, a 1,500 kVA transformer was ultimately chosen.
That 1,500 kVA figure came from project judgment, not directly from the kW-to-kVA formula. It was an equipment-selection decision based on the project's requirements, expected load growth, operating conditions, available capacity, and long-term reliability.
That's an important distinction in practical electrical work:
The calculated kVA tells you the apparent power requirement for the stated load and PF. It doesn't automatically determine the final transformer rating.
The final selection needs a proper engineering assessment.
Why Connected Load Alone Can Mislead You
I've seen equipment selected by simply adding the nameplate ratings and choosing a generator or transformer around that number.
A factory may have:
- CNC machines
- Robotic systems
- PLC panels
- Air compressors
- Pumps
- HVAC
- Industrial heaters
- Welding equipment
- Lighting
- Cooling systems
Not all of them operate at the same time or at their full nameplate rating.
Some loads can also create short-duration starting or load-step requirements.
When reviewing a real plant, I don't look at one number and stop there. I want to know what's installed, what's normally running, what starts together, what PF is being measured, and what the plant is expected to add later.
kW to kVA for Generators
Generator capacity is commonly specified in kVA, while the real-power output is expressed in kW.
Suppose the load is:
100 kW at 0.8 PF
The calculated apparent power is:
100 ÷ 0.8 = 125 kVA
That doesn't automatically make a 125 kVA generator the correct choice.
A generator assessment may also need to consider:
- Running load
- Motor starting
- Compressor starting
- HVAC starting
- Load-step response
- Connected load
- Future expansion
- Generator rating
- Site conditions
- Operating hours
- Fuel consumption
- Manufacturer requirements
A generator can have sufficient steady-state capacity for a load and still need additional consideration for motor starting or other large load steps.
Use our online AC Tonnage Calculator to get results in seconds.
Generator Fuel Consumption Matters Too
Another practical question is often missed:
At the expected load, how much fuel does the generator burn per hour?
If a generator operates for many hours every day, fuel cost can become a large part of the operating cost.
When comparing generator options, check the manufacturer's fuel-consumption data at realistic loading points. A generator's fuel consumption isn't represented accurately by one litres-per-hour figure for every operating condition.
kW to kVA for Transformers
Transformers are commonly rated in kVA.
Suppose:
Load = 500 kW, PF = 0.9
Then:
kVA = 500 ÷ 0.9 = 555.56 kVA
This gives the apparent power requirement at that operating point.
The transformer selection still needs an engineering review covering load growth, voltage, operating conditions, temperature, system configuration, harmonics where relevant, and the manufacturer's rating.
Transformer manufacturers publish ratings in kVA across a wide range of applications. Eaton, for example, lists distribution transformers with ratings expressed in kVA. (Eaton)
Why a Transformer Shouldn't Be Selected From kW Alone
Imagine two plants, both consuming 500 kW.
Plant A operates at PF 0.98.
Plant B, on the other hand, runs at a PF of 0.80.
Their apparent-power requirements are:
Plant A: 500 ÷ 0.98 = 510.20 kVA
Plant B: 500 ÷ 0.80 = 625 kVA
Same real power. But the apparent-power figure moves.
That's why PF can't be left out of the calculation.
CNC Machines, PLCs and Robotic Systems
Industrial automation makes load assessment more interesting.
A CNC machine may have a spindle motor, servo drives, coolant pump, hydraulic equipment, lubrication system, control electronics, fans, and other auxiliary loads.
A robotic cell can include servo motors, controllers, conveyors, welding equipment, tooling, safety systems, and auxiliary machinery.
If you only look at one nameplate value, you may miss part of the electrical picture.
For a plant with many machines, measured electrical data can be much more useful than simply adding every nameplate rating.
Industrial Heaters and HVAC Loads
Another common mistake is focusing heavily on motors and production equipment while forgetting other loads.
An industrial heater can have a large real-power requirement. A resistive heating load can have a PF close to unity, so its kW and kVA values may be close.
HVAC systems can behave differently because compressors, fans, pumps, drives, and controls all contribute to the electrical load.
A complete load schedule should account for the whole system, not just the main production equipment.
When Do kW and kVA Match Up?
They match only at a power factor of 1.0.
When PF = 1:
kVA = kW ÷ 1
So 100 kW works out to 100 kVA.
At PF = 0.8, that same 100 kW becomes 125 kVA — the gap comes entirely from the power factor.
Converting kVA Back to kW
Flip the formula:
kW = kVA × PF
Say a generator is rated at 500 kVA and operates at 0.8 PF — real power comes out to 500 × 0.8 = 400 kW.
kW to kVA Reference Chart
Figures below assume a power factor of 0.8.
| kW | kVA |
|---|---|
| 5 | 6.25 |
| 10 | 12.50 |
| 15 | 18.75 |
| 20 | 25.00 |
| 25 | 31.25 |
| 30 | 37.50 |
| 40 | 50.00 |
| 50 | 62.50 |
| 60 | 75.00 |
| 75 | 93.75 |
| 80 | 100.00 |
| 100 | 125.00 |
| 125 | 156.25 |
| 160 | 200.00 |
| 200 | 250.00 |
| 250 | 312.50 |
| 315 | 393.75 |
| 400 | 500.00 |
| 500 | 625.00 |
| 625 | 781.25 |
| 1,000 | 1,250.00 |
The chart changes when the PF changes, so don't use a 0.8 chart for a load that actually operates at 0.95 PF.
kW to kVA Conversion at Different Power Factors
| kW | PF 1.0 | PF 0.95 | PF 0.90 | PF 0.80 |
|---|---|---|---|---|
| 10 | 10.00 | 10.53 | 11.11 | 12.50 |
| 25 | 25.00 | 26.32 | 27.78 | 31.25 |
| 50 | 50.00 | 52.63 | 55.56 | 62.50 |
| 100 | 100.00 | 105.26 | 111.11 | 125.00 |
| 250 | 250.00 | 263.16 | 277.78 | 312.50 |
| 500 | 500.00 | 526.32 | 555.56 | 625.00 |
| 1,000 | 1,000.00 | 1,052.63 | 1,111.11 | 1,250.00 |
The effect of PF becomes more noticeable as the load gets larger.
Which Power Factor Value Should You Use?
Use the actual PF when you have it.
Useful sources include:
- Equipment nameplate data
- Manufacturer documentation
- Generator specifications
- Electrical meters
- Power-quality analyzers
- Plant monitoring systems
- Measured operating data
For a mixed industrial plant, one PF value may not describe every individual machine. A measured plant PF can be useful for a plant-level calculation, while individual equipment may need its own electrical data.
Don't automatically enter 0.8 just because you've seen that value on generator specifications.
What Changes When Power Factor Gets Better?
Consider a load of 100 kW.
At PF 0.80: 100 ÷ 0.80 = 125 kVA
At PF 0.95: 100 ÷ 0.95 = 105.26 kVA
At PF 0.99: 100 ÷ 0.99 = 101.01 kVA
The real power stays at 100 kW, while the apparent-power requirement gets smaller as PF moves closer to 1. Power-factor correction can reduce the apparent power and current requirements seen by the supply, although the correct correction equipment and settings require a separate electrical assessment. Eaton's power-factor guide gives the same relationship between kW, kVA, and PF. (Eaton)
kVA and Electrical Current
Once you've calculated kVA, you can use it for current calculations when the system voltage and phase configuration are known.
For a single-phase system:
kVA = V × A ÷ 1,000
For a three-phase system:
kVA = √3 × V × A ÷ 1,000
So voltage isn't required for the basic kW to kVA calculation, but it becomes necessary when you're calculating current from kVA.
This distinction is useful when moving from an equipment capacity calculation to breaker, conductor, or distribution-system calculations. Eaton provides the corresponding single-phase and three-phase relationships in its power-factor engineering guide.
Common kW to kVA Mistakes I See in Industrial Work
#1. Treating kW and kVA as the Same
They're equal only when PF is 1.0.
#2. Ignoring Power Factor
A lower PF increases the kVA requirement for the same kW.
#3. Confusing Connected Load With Running Load
A plant can have a large installed capacity while operating at a much lower load at a particular time.
#4. Selecting a Generator Without Checking Starting Requirements
Large motors, compressors, pumps, and similar equipment can create starting demands that need to be evaluated separately from steady-state load.
#5. Forgetting Auxiliary Loads
HVAC, heaters, pumps, compressors, lighting, controls, and cooling systems can add a meaningful amount of load.
#6. Ignoring Fuel Consumption
A generator's kVA rating tells you about electrical capacity. It doesn't tell you the complete operating cost.
#7. Selecting Equipment Only From the Calculated kVA
The calculated kVA is one input to equipment selection. The final rating depends on the actual application and project requirements.
Is the kW to kVA Calculation Enough for Equipment Selection?
No.
The calculation gives you the apparent power for a specified real-power load and PF.
A proper generator or transformer assessment may also consider:
- Running load
- Connected load
- Maximum demand
- Motor starting requirements
- Future expansion
- Load diversity
- Power factor
- Voltage
- Frequency
- Harmonic or nonlinear loads
- Ambient conditions
- Manufacturer ratings
- Site requirements
A calculator is useful for the conversion. It isn't a replacement for a complete electrical design review.
How to Use the kW to kVA Calculator
Step 1: Enter the kW
Enter the real power of your load in kilowatts (kW).
Step 2: Enter the Power Factor
Enter the actual PF of the equipment or electrical system.
Step 3: Calculate
The calculator divides the kW value by the PF.
Step 4: Review the kVA
The result gives you the calculated apparent power in kilovolt-amperes (kVA).
If you're using that number for a generator or transformer project, review the actual operating conditions before choosing the final equipment rating.
Frequently Asked Questions
How many kVA is 100 kW?
It depends on the PF. At PF 0.8: 100 kW = 125 kVA. At PF 0.9: 100 kW = 111.11 kVA. At PF 1.0: 100 kW = 100 kVA.
Is 1 kW equal to 1 kVA?
Only when the PF is 1.0.
What is 100 kW at 0.8 PF in kVA?
100 ÷ 0.8 = 125 kVA
What is 500 kW at 0.8 PF?
500 ÷ 0.8 = 625 kVA
Why are generators rated in kVA?
kVA describes apparent power, which is related to the voltage and current that the generator supplies. Generator manufacturers publish ratings in kVA along with other operating specifications.
Why are transformers rated in kVA?
Transformer capacity is commonly expressed in kVA because the electrical loading is associated with voltage and current, while the real-power portion also depends on the load PF.
What PF should I use for a generator?
Check the generator manufacturer's rating and the actual load characteristics. Many conventional generator specifications use 0.8 PF as a reference rating, but you should always verify the specific model. Caterpillar, for example, publishes generator test information at both 0.8 and 1.0 PF on some models.
Final Takeaway
A kW to kVA calculator makes the mathematical part quick:
kVA = kW ÷ PF
The formula itself isn't complicated. The engineering judgment comes when you decide which load value to use and what the calculated kVA means for the actual installation.
For a small electrical load, the calculator may be all you need. For a factory, generator, transformer, CNC production line, or large commercial installation, review the calculated kVA alongside connected load, running load, PF, starting demand, future expansion, voltage, operating conditions, and equipment specifications.
Use the kW to kVA calculator for the conversion, then evaluate the actual application before selecting electrical equipment.
Disclaimer: This kW to kVA calculator is provided for general information and estimation purposes only.
Results depend on the values entered, including power factor, and may not reflect actual operating conditions.
Don’t use the result alone to select generators, transformers, cables, or other electrical equipment.
Always consider load conditions, starting requirements, voltage, applicable codes, and manufacturer specifications.
For critical installations, consult a qualified electrical professional before making equipment-selection decisions..
