# Meaning of 1 unit Electricity (Calculation of Power and Electricity Bill)

## What is the meaning of 1 unit electricity?

1 unit electricity is the amount of electrical energy consumed by a load of power rating 1 kW in 1 hour. In electrical engineering, the consumption of electrical energy is measured in terms of kWh. Whereas in general practice, We all understand the consumption of electrical energy in multiple of 1 unit. It means if we talk about 1 unit of electricity in general then technically it is understood that 1 kWh of electrical energy. Hence technically we can say that 1 unit electricity is equal to 1 kWh (kilowatt hour).

Since, 1 unit of electricity = 1 kWh

= 1000 W * 1 hour

= 1000 W * 60 * 60 sec

= 3.6 * 106 joule

Hence it means 1 unit of electricity will be equal to 3.6 * 106 joule of electrical energy.

1 Unit = 1 kWh = 3.6 * 106 joule

## Calculation of power consumption

Power consumption means it is basically the consumption of electrical energy for a specific period of time. Hence when we talk about power consumption calculation then it means we have to calculate electrical energy consumed for that period of time. So the power consumption of any electrical appliances is technically measured in kWh ( or multiple of 1 unit ) that is displayed in kWh in the energy meter reading.

To calculate the consumption of electrical energy for a specific period of time ( say 1 month ), follow these steps:

• Step 1: Note down the initial and final reading of the energy meter for a specific period of time ( say 1 month ).

Let’s suppose that the initial reading is A kWh and the final reading is B kWh.

• Step 2: Take the difference between the final and initial reading that will give you the total power consumed for that period of time ( 1 month ).

Here total energy consumed will be ( B-A ) kWh for that month.

Since 1 kWh = 1 unit, in other words, we can say that the total energy consumed will be ( B-A ) units.

## Calculation of electricity bill

Either for simplicity, you can use the electricity bill calculator provided on the official website by your electricity board. Or you can calculate your current month’s electricity bill manually with the help of an electricity tariff fixed by your electricity board.

Now let’s consider the tariff data and other fixed charges of any electricity utility company as an example to calculate the electricity bill amount. Follow these steps:

• As explained above to calculate the power consumption of the current month you need to take the difference between the current month’s reading and last month’s reading [ say (B-A) units ].
• Once you get the exact energy consumption, you can easily calculate the energy charge by multiplying total units with slab-wise per-unit charge fixed by your electricity board.
• For example suppose slab-wise charges of electricity company are: Rs. 4 for 1-100 units, Rs. 5 for 101-200 units, Rs. 6 for 201-300 units etc.
• If you have consumed 260 units then your energy charges will be Rs. ( 100*4 + 100*5 + 60*6 = 1260 ).
• Finally, the total electricity bill amount will be calculated by adding fixed charges (say Rs. 50) and energy duty of Rs. 52 (say 0.20 per unit). Thus total electricity bill amount will be (1260 + 50 + 52 =1362). 