How To Calculate Consumption of Electricity in Units in Houses

In India, the 'Electricity Charges'  are made for ‘units’ of electricity consumed. The rate of charges per unit is different in different states of India.



What is one unit of electricity?

The various electrical equipments used in our houses consume various amount of electricity.   The power of electric equipments are measured in ‘watts’.

One unit of electricity will be consumed when 1000 watts of an electric equipment / total of  1000 watts by various equipments is used for one hour.

To  calculate our monthly /bi-monthly consumption of electricity we must know the power of various electric equipment we use in our houses.

The following are the power of various electric equipments:


Lamps (Bulbs)- 60  watts



Lamps (CFL)- 15 watts



Tube Lights- 40  watts


Electric iron     box- 750 watts







Immersion heater-    1000 watts





Water heater/Geyser-2 000 watts


Instant Geyser- 3000 watts-

Refrigerator (165 liters )-150 watts


Window air -conditioner -( 1.5 ton)    -2650 watts


Room cooler ( medium)-    200 watts



Table fan/ceiling fan- 75 watts



Exhaust fan-  150 watts

Washing machine-     400 watts


Television-    100 watts


Mixer-  500 watts




Wet Grinder- 300 watts


Microwave oven-     1200 watts



Computer-     200 watts


Mosqutio Repeller    -9 watts


Pump motor (1 HP)    -740 watts

Mobile /Battery Charger-    7 watts

Let us now take an example as below:-

In a house, let us say, the following electrical equipments are used:

• 4 tube lights (used daily for 6 hours)-(4x40x6x30)/1000=28.8 units
• 4 bulbs (used daily for 2 hours)-(4x60x2x30)/1000=14.4 units
• 4 fans(used daily for 15 hours)(4x75x15x30)/1000=135 units
• 1 Television(used for 12 hours)(1x100x12x30)/1000= 36 units 
• 1 Refrigerator( used for 24 hours)(1x150x24x30)=108 units

Total Consumption of electricity will be 322 units/320 units for 1 month and 640 units bimonthly.

If and when Air Conditioner/s, Pump-Motors, Washing Machines are in regular use in a house, the consumption of electricity will be high and the EB bill will also be very high,in view of the increased rate per unit for higher slabs of use of units.