Electricity Saving Tips For Homes And Offices

What are Watt, Kilowatt and a unit of electricity

By on May 3, 2015

When we get our electricity bills, it shows that we have used a certain number of units for the given period. When we go to buy appliances, most of them have watts mentioned on them. If you find it difficult to understand the relation between the two, then you are not alone. Electricity bill and its components are confusing to many and with this article we will try to explain what are watt, kilowatt and a unit of electricity.


Power and Energy/Electricity

Power and Energy/Electricity are two words that are used so much for each other that many feel that they mean the same. Interestingly both of them have a very different meaning. Power is the rate at which electricity is used and energy/electricity is the actual consumption. To give an analogy, power is similar to speed but electricity/energy is the actual distance travelled.

So        Power x Time = Electricity (or energy)

Just like          Speed x Time = Distance Travelled.

Power and its units

Power is always represented in watt (W) or kilowatt (kW). A thousand (1000) watts make one kilowatt. So if any appliance is rated as 1.2 kW then it means that it consumes electricity at a rate of 1200 W. Now as we discussed earlier that power is the rate at which electricity is consumed and not the actual electricity consumed, Watt or Kilowatt just represent the rate at which electricity is consumed per hour. Which means that when you buy a 100 W bulb, it does not consume 100 units of electricity but consumes at a rate of 100 W.

Energy/Electricity and its units

A unit (as mentioned on the electricity bills) is represented in kWH or Kilowatt Hour. This is the actual electricity or energy used. If you use 1000 Watts or 1 Kilowatt of power for 1 hour then you consume 1 unit or 1 Kilowatt-Hour (kWH) of electricity. So the reading on the electricity meter represents the actual electricity used. Just like the odometer on your vehicle that shows the actual distance travelled by the vehicle, electricity meter shows the amount of electricity that is used. So a 100-Watt bulb if kept on for 10 hours will consume:

100 x 10 = 1000 Watt-Hour = 1 Kilowatt-Hour (kWH) = 1 units (on your meter).

Estimating units consumed by any appliance

Now with most of the concepts explained we would like to make it easy for you to calculate how much units does any appliance consume. Most appliances have wattage written on them (either on their container box or somewhere on the appliance). Once you have the wattage, next you need to figure out how many hours a day do you use it. After that you can use the formula below:

Daily Units = (Wattage x Usage hours per day) ÷ 1000

Monthly Units = Units x 30 (or 28,29,31 based on month)

Please note that this formula may not work always. For appliances like Air Conditioner, Water Heater, Cloth Iron (any heating or cooling device) and pumps, this will not work.Infographic3

Source of Information:



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59 Comments on "What are Watt, Kilowatt and a unit of electricity"

If you have any question or comment, please leave a message here. We try to reply to questions in the sequence they come in. We work from Monday-Friday 10AM-7PM. If we know the answer we try to reply to the question within 3 days.

arsh aftab
May 24, 2015

sir ,
mere 1.5 ton split ac hai. jo ki 1900 watt ka hai . mujhe 8-10 hour chalana hai .mere month me kitne unit kharch hoga.

May 7, 2015

Dear Sir,
A Machine run at the power of, 8.2kw / 380v / 50Hz,

Can you please help me to know how much units of electricity it will consume in one hour?

May 8, 2015

Thank You.

May 4, 2015

i forgot to switch off iron box(without using) for 14 hr dos my electricity bill will increase very high

May 4, 2015

thank you sir

Digambar S Phule
April 29, 2015

my office use 1200 units electricity per month so i want know how many kilowatt we use per month

Nisarg J
April 27, 2015

Dear Sir, I have a single phase connection at my appartment and my alloted load is 3kw in gandhinagar kudasan. Our electricity provider is ugvcl. Now I want to install 3split ac and 3 water heaters. My question is do I need to change the entire wiring of my house? What is the procedure to increase my load to 10kw with ugvcl? How much do I have to spend for this entire procedure.?

April 23, 2015

Will u tell me which ac consume more electricity window one or split one……if both of them having same rating and both of them are use same no. Of hours in a day…

March 22, 2015

Hi Abhishek, those articles are very helpfull, for a common person to understand the daily usage of their home appliances …

thanks for sharing… :)

Kamlesh Gadaria
May 19, 2015

Hi Abhishek,

This Information is Very Helpfull for Buying Any Home/Office Application.

April 20, 2015

thanks to solve my doubt

Shubham Singh
March 15, 2015

Correction in the line “Watt or Kilowatt just represent the rate at which electricity is consumed per hour”, it is actually per second not hour. 100 Watt means 100 Joule per second energy… by the way nice article, keep on posting.

March 14, 2015


Shubham Singh
March 15, 2015

1 Unit = 1 Kilo Watt hour(kwh) = 1000×3600 Joule per sec
5KW = 5000 J/s = 5000/3600000 Unit = 0.0014 unit
it means that if you use 5 KW of power for 1 second then it will consume 0.0014 unit
i hope you got it…

January 21, 2015

Hi how to find the electricity meter number and unit consumption in a digital meter.?