Difference Between KW, KVA, KWH, KVAH (With Simple Examples

Whenever you see symbols like “KW“, “KVA“, “KWH “& “KVAH“. It feels like; these all are linked with Electricals even when you do not belongs to Electrical field.

All these four terms are inter-related. Many people get confused between kW, kVA, KWH, and KVAH. However, each term has a different meaning and application in Electrical systems.

In these post, We are going to discuss all these terms in most simpler way.

TABLE OF CONTENT OF THE POST :

Definition of KVA, KW

KVA

KVA stands for “KILO VOLT AMPERE“. It is the unit of “Electrical power“. Technically, This term KVA is known as “Apparent power“.

• KVA – “KILO VOLT AMPERE” Where K is multiples of a unit of measurement
• KVA – 1000* Voltage*Current (Single phase power)

The power generating machines such as “Alternators” and power transferring electrical machines such as “Transformers” are rated in “KVA“. Apart from minor losses, These machines do not consume any type of Electrical power.

An image of name plate of 1100VA UPS is shown below.

KW

KW stands of “KILO WATT“. It is also the unit of “Electrical power“. Technically this term KW is known as “Active power“.

• KW- “KILO WATT“
• KW- 1000*Voltage*Current*Power factor (Single phase AC power)
• W(Watt)- Voltage*current (DC power)

The power consuming Electrical machines such as Motors, Heaters, Compressors are rated in KW. An image of name plate of 5.5 KW Induction motor is shown below.

In KVA and KW, There is one term which is creating the difference and that term is “Power factor“. Power factor reduces the KVA power down to KW power. In short, We can say ‘ KVA is the input power from power generating system. While KW is consumed power by an Electrical load. The remaining power is known as “Reactive power (KVAR)”.

• KVA is sum total of “KW + Reactive power”
• KVA²=KW²+KVAr²
• Apparent power²=Active power²+Reactive power²

Power factor

Power factor (PF) is the angular term Which exist across AC power only, Because of frequency. Since DC power has 0 frequency that’s why DC power independent of power factor.

• DC power= Voltage*Current
• AC power(single phase)= Voltage*Current*Power factor

POWER FACTOR :

• The term Power factor is the ratio of “Active power” to “Apparent power“.
• Power factor is a cosine angle in between voltage & current. Represented with a symbol Cos(θ).
• KW/KVA or KWH//KVAH
• The value of Power factor varies from 0 to 1.
• 0 Power factor is the lowest one.
• 1 is the maximum value. Power factor 1 is also known as unity Power factor.
• At 1 Power factor(unity) true power becomes equal to apparent power.

In an AC power, When power supply (KVA-apparent power) get applied across an Electrical load. It consumes power (KW-Active power). But there is one more power which flow across the circuit & that is reactive power (KVAR). Reactive power depend upon the load Whether it is going to be neutral (Resistive load) , Or Whether it is going to be lagging (Inductive load), or Whether It is going to be leading (Capacitive load).

Real-Life Analogy of power factor

Imagine a glass of cold drink with foam on top:

• Useful drink = kW
• Foam = Reactive Power KVAR
• Total glass content = kVA

Definition of KVAH & KWH

KVAH & KWH both are Electrical energy units. These terms reflects the power flow over the time. Next these terms are going to be discussed on by one.

KVAH

KVAH stands for “KILO VOLT AMPERE HOUR”. It is the energy unit of “Apparent power“. The power providing utility charges on these energy units, mostly.

KVAH energy is the sum total of “Active energy” & “Reactive energy“.

KWH

KWH stands for “KILO WATT HOUR“. It is the energy unit of “Active power“. The electrical appliances consumes this power.

In shot; We can say’

• KVAH is the input Energy to the system which is been charged.
• KWH is consumed energy by an Electrical load.
• KVARH is the energy which flow across the circuit.
• KVAH is the sum total of “KWH + KVARH” such as KVA²=KW²+KVAr²

• An image of energy meter by RISH delta energy is shown above. Meter shows the reading 66.30KVA, 66.26KW, 2.354KVAr.
• KVA²=KW²+KVAr²
• PF=KW/KVA=0.999

Difference Between KW, KVA, KWH, KVAH in a tabular form

PARTICULARS	KVA	KVAH	KW	KWH
Definition	Apparent power	Apparent power/hour	Active power	Active power/hour
Full form	Kilo volt ampere	Kilo volt ampere hour	kilo watt	Kilo watt hour
Type	Power	Energy	Power	Energy
Comparison	≥ KW	≥ KWH	≤KVA	≤KVAH
Power factor	Independent	Independent	dependent	dependent
Rating of a machine	Transformers & alternators	–	Electrical motors, heaters, Induction	–
Mathematically	V*I*1000	V*I*1000*hour	V*I*1000*power factor (single phase)	V*I*1000*power factor*hour (single phase)
Reactive power	Dependent	Dependent	Independent	Independent

Final Conclusion

• The post explains the differences between four key electrical terms: KW, KVA, KWH, and KVAH.
• KW (Kilo Watt) is the unit of active power consumed by electrical devices like motors and heaters.
• KVA (Kilo Volt Ampere) is the unit of apparent power, used mainly for generators and transformers.
• KWH is the unit of energy consumed
• KVAH represents the total energy over time, including KWH & reactive power.
• In simple terms, kW and kWh represent actual useful power and energy, while kVA and kVAh represent total supplied power and energy including reactive components. Understanding these terms is important for electrical calculations, equipment sizing, and electricity billing.
• Power factor, which measures the efficiency of power usage, influences the relationship between KW and KVA.