# How To Calculate Power Consumption Of Any Appliance Share the article

Ever wonder how much electricity the light bulb in your kitchen consumes or how much power your washing machine, air conditioner, and refrigerator consume? In this article, we will see how to calculate the power consumption of household appliances.

To calculate power consumption of any appliance, you have to multiply it’s wattage by the number of hours it is being used (operational hours).

For example, a 1000 watt electric iron running for one hour will consume (1000 watt X 1 hour) 1000 watt hour or 1 kilowatt hour (kWh) of electricity. Similarly, to calculate the monthly power consumption multiply the daily power consumption by 30 days and for annual power consumption multiply the daily power consumption by 365 days.

To know how much it will cost you to run any appliance, just multiply its power consumption by your electricity tariff.

Before we start with the calculation there are a few things you need to know.

## Things To Know Before Calculating Power Consumption of any appliance:

1. Wattage Of The Appliance: Wattage is the rated power of the appliance. For example, a LED TV’s wattage ranges from 50 watts to 200 watts. Wattage gives us an indicator of the rate at which the appliance will consume power. From the above example, a 50-watt television will not consume 50 units of electricity, instead, it means the TV will consume electricity at 50 watts per hour.
2. Operational Hours: Operational hours are the number of hours a device/appliance is in operation. For example, if you want to measure the power consumed by your ceiling fan in 5 hours, the operational hours are 5 hours.
3. Kilowatt Hours: Kilowatt hours or units of electricity is the energy consumption of a device. For example, a 50-watt table fan running for 50 hours will consume 50 watts x 50 hours = 2500-watt hours = 2.5-kilowatt hours of electricity = 2.5 units of electricity. (1 kWh of electricity = 1 unit of electricity)

To know your operational hours is pretty easy but what about wattage, let’s see how to find the wattage of any appliance.

### How To Know The Wattage Of An Appliance:

Every electrical appliance we use has a technical specification sticker at the bottom or on its back. You can find the wattage of an appliance on that sticker.

Most appliances will have direct wattage mentioned in the sticker, but sometimes you will get the operating voltage and rated current, for those cases just multiply volts by current to calculate the wattage.

Wattage of an appliance = Voltage X Current

If for some reason you can’t find the wattage from the sticker, then just go to Amazon and search for the appliance (a similar one will also work) and check out its wattage from the product description. You can also go to the appliance manufacturer’s website to get an accurate value.

If this sounds like a lot of work then check out this article – Wattage of household appliances.

## Calculate the Power Consumption of Any Appliance:

Now that you know how to find the wattage of an appliance let’s see how to calculate power consumption.

Power consumption of an appliance – Wattage of the appliance X Operational hours

Let’s see some examples,

Example 1: Power consumed by a 100 Watt LED TV running for 24 hours a day for the entire month (Netflix Binge Watch !!)

• The wattage of the appliance – 100 watts.
• Operational hours – 24 X 30 – 720 hours in a month.

Power consumption of an appliance – Wattage of the appliance X Operational hours

Power consumed by a 100-watt TV = 100 Watt X 720 Hours.

Power consumed by a 100-watt TV = 72,000 Watt Hours = 72 kWh.

( 1 kilowatt hour (kWh) = 1000 watt hour)

Example 2: A 1000-watt water heater running for 1 hour daily for the entire month.

• The wattage of the appliance – 1000 watts.
• Operational hours – 1 X 30 – 30 hours in a month.

Power consumed by a 1000-watt water heater= 1000 Watt X 30 Hours.

Power consumed by a 1000-watt water heater = 30,000 Watt Hours = 30 kWh.

Using this method you can get an approximate idea about the power consumption of common household appliances, but you will get vastly inaccurate results for appliances with compressors like your refrigerators, and air conditioners.

The reason for this is, compressors, which are the most power-consuming part of these appliances don’t run all the time. For example, a refrigerator is never off, it works 24X7, but its compressor work just 1/3rd of the time, the rest of the time it’s off. (If you notice carefully you can even listen to the compressor turning on & off).

We will discuss how to calculate the power consumption of appliances with compressors in the later part of the post.

Now that you know how to calculate the power consumption of an appliance, let’s calculate the amount of electricity bill you will get for using that appliance.

## Calculate The Electricity Bill You Get For Using Appliances:

To calculate the amount of electricity bill you will get for using an appliance just multiply the power consumption of the appliance by the electricity tariff.

Electricity Bill For Using An Appliance = Power Consumption Of The Appliance X Electricity Tariff

Electricity Tariff – The electricity tariff is the amount your electricity provider charges you for one unit of electricity. I live in Mumbai, India here the electricity tariff is Rs 11 / kWh.

To find your electricity tariff, just look into your previous month’s electricity bill and find out your monthly electricity consumption, then just divide your monthly electricity consumption by your total monthly electricity bill, the figure you get is approximately your electricity tariff.

You can also check out the following articles to know your electricity tariff.

Now let’s see how much it will cost to run an appliance.

let’s take the above 100 Watt LED TV example,

As we calculated before, a 100-watt LED TV running 24 hours a day will consume 72 kWh in a month.

Hence, the Total monthly electricity bill for using this 100-Watt LED TV = 72 kWh X Rs 11 / kWh = Rs 792.

(Now you know how much it will cost you to binge-watch Netflix for the entire month.)

I have made a simple calculator for you guys, just type in the wattage of your appliance, daily operational hours, and electricity tariff and it will show you the daily, monthly, and annual power consumption of that appliance.

### How To Calculate Power Consumption of Appliances with Compressors:

As I said before the exception to the above calculation is appliances with compressors in them.

The reason is, compressors, which are the most power-consuming part of these appliances don’t run all the time. For example, a refrigerator is never off, it works 24X7, but its compressor work just 1/3rd of the time, the rest of the time it’s off. (If you notice carefully you can even listen to the compressor turning on & off).

Hence, if you have a 1 Ton AC which translates to roughly 800 watts and you run it for 5 hours daily for the entire month then,

AC’s Monthly power consumption = 800 watt X 150 hours = 1,20,000 watt hour = 120 kWh

But in reality, the value will be lower than this.

For refrigerators, you can divide the calculated answers by 3 to get an approximate power consumption.

For air conditioners, you can divide the calculated answers by 2 to get an approximate power consumption.

Luckily, most high power-consuming appliances are BEE rated and they have an energy sticker on them that shows their annual power consumption and other useful details.

The annual power consumption is calculated in standard operating conditions and 1600 hours of annual operation hence, the values will vary on the number of hours you use the appliance and operating conditions (slightly higher in real-life scenarios for the same operational hours). 1 Ton Split Inverter AC Annual Power Consumption is 598 kWh

This theoretical method of calculating power consumption will give you approximate results as the power consumption of an appliance depends on a lot of factors like the operating conditions, the way it’s being used, how old the appliance is, and many other things.

Hence, the best and by far the most accurate way of calculating the power consumption of any appliance is by using a simple Kill A Watt meter.

### Calculate The Exact Power Consumption Of Any Appliance Using Kill A Watt Meter:

Kill A Watt Meter is a simple device that gives real-time data on the power consumption of any device.

You can buy it from amazon using this link. Best Kill A Watt Electricity Usage Monitor

To use a kill-a-watt meter to calculate the power consumption of an appliance, first, connect the appliance plug into the kill-a-watt meter and then plug the kill-a-watt meter in your wall socket and you are good to go.

Then start using the appliance and you can see in real-time how many kWh (units) of electricity it is consuming.

For appliances that have compressors like refrigerators and ACs, it is advisable to take the reading for 4-8 hours to get exact power consumption.

## Power Consumption Of Common Household Appliances:

I have made detailed articles on the power consumption of almost all household appliances with some useful tips to reduce your electricity consumption. Hence, feel free to browse through the following articles. (I keep adding more articles to this list every week)

If your electricity bill is high then check out this article – Why my electricity bill is so high?