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Watt conversion calculator

As electricity measurement unit, the Watt is the measurement unit used to measure the power used by the smaller home appliances. 

For example, the electricity usage of a toaster, kettle, clothes iron, computer monitor or the desktop printer are measured in Watts.

If you are interested to know how to reduce the electricity usage and the electricity bill, you need to learn what a Watt is.

What is a Watt

A watt (W) it is a unit used to measure power.

A Watt it is the amount of energy that our household appliances and devices need to function, the rate at which they consume energy.

One watt is the equivalent to electricity flowing at a rate of one joule per second.

For example, a light bulb rated at 60 W will need that much amount of power to be able to produce a predetermined amount of light (lumens).

light bulb lumen and watts comparison table

The following YouTube video explains what a watt is and how it is related to other power measurement units and our household appliances and devices. Do not forget to enable the video captions, as the video caption contains the concepts explanations.

What is a Kilowatt hour (kWh)

Conversion calculator to convert Watts to other units

Watt (W) to Kilowatt (kW) conversion calculator

To convert Watts (W) to Kilowatts (kW) you need to divide the number of Watts by 1000.

kW = W/1000


For example, if a device uses 300 Watts but we need to know how much is that in Kilowatts:

300/1000 = 0.3 kW 

Watt (W) to Kilowatt hour (kWh) conversion calculator

To convert Watts (W) to Kilowatt hours (kWh) you need to divide the number of Watts by 1000 and afterwards multiply the result by the number of hours.

kWh = (W/1000) x Hours

kWh is the measurement unit used by the electricity suppliers to calculate our electricity bills. 

Also, most of the big appliances, like the dishwashers or washing machines, rate their consumption in kWh.


For example, if a device uses 300 Watts and has been in use for 5 hours:

(300/1000) = 0.3 kW

0.3 kW x 5 hours = 1.5 kWh 

Watt cost calculator

The electricity cost is calculated based on the number of Kilowatt hours (kWh) that an appliance, device or household uses.

Still, if you need how much you are paying per Watt (W) or more specifically per Watt-hour (Wh), you need to divide how much your are payment per kWh by 1000.


If you don’t know how much you are paying per kWh, you should be able to find the cost per kWh on your electricity contract or in one of the electricity bills.

As an example, the user from the picture below is paying 31,90 cent per kWh.

Nowadays it is very common that the electricity contract details, the monthly or yearly electricity usage and electricity cost can be access online.

how much does electricity cost

Alternatively, if don’t have access to your contract or your electricity bills, this website does show the electricity cost per country.

Watts-hour (Wh) to Amps-hour (Ah) conversion calculator

To convert Watts-hour (Wh) to Amps-hour (Ah) you need to divide the Watts-hour by voltage.

Ah = Wh/V


For example, if a device uses 350 Watts per hour in a country were the power supply is 220 Volts:

350 Wh / 220 V = 1.591 Ah

Watt (W) to Amp (A) conversion calculator

To convert Watts-hour (Wh) to Amps-hour (Ah) you need to divide the Watts-hour by voltage.

A = W/V


For example, if a device uses 350 Watts in a country were the power supply is 220 Volts:

350 W / 220 V = 1.591 A

A few other examples from our ‘Electricity usage and electricity cost calculators‘ page that may be of your interest:

Watt electricity usage monitor

If you want to know how many watts does an appliance or device use, your best option is to use a plug in power meter to measure the electricity consumption. 

Clicking on the image below it will redirect you to the Amazon page where you can have a look to the specifications of the power meter we use for our measurements.

plug in power meter

All of our house appliances and devices like the washing machine, the dishwasher, the TV or the printer are plugged to a wall socket. 

So, with a power consumption meter we can determine how much electricity our appliances or devices are using and, more importantly, we can measure the electricity usage over a period of time.

If you want to find out how you can use a plug in power meter to measure your electricity usage and electricity cost, have a look to this YouTube video.

Plug in power meter

Watt FAQ

How many watts is a kilowatt

A kilowatt is equal to 1000 watts.

How much is a kilowatt of electricity

It depends on the contest.

In terms of money, the cost of a kilowatt hour depend on where you live or even the contract you have with the electricity provider. For example, in Germany in 2021 the average cost per kilowatt hour is 33 cents.

In terms of quantity, an small electric fan uses around 50 Watts an hour so it will take it 20 hours of use to use one kilowatt.

Instead, an air conditioner can use around 1500 Watts an hour so it will take less than one hour of use to use one kilowatt.

Watt and energy conservation

Energy conservation can be defined as the decision and the act of using less energy

Energy conservation both benefit you and the environment

The act of saving and conserving electricity does benefit you because you will be paying less on your energy bills. 

And it also does benefit the environment because conserving electricity prevents any unnecessary waste of natural resources.

Now, at individual level it may not look worth to try to save a few watts here or there. 

Still, every little counts and if hundreds or thousands of us do save a little every time, it will make an important contribution towards conserving our natural resources.


For example, if 9000 households would manage to save as little as 10 Watts per day (0,01 kWh) that would add to 32850 Kilowatt hour (kWh) saved per year. 

9000 households x 0,01 kWh per day x 365 days per year 

32,850 kWh saved per year

That is a considerable amount of electricity, but let’s add additional perspectives for clarity:

> Assuming an average cost of 0,18 euro (or dollars, or pounds, or any other currency) per kWh, we would collectively be saving nearly 6000 euro per year.

> To produce 32,850 kWh of electricity it is necessary to use around 17 metric tons of coal or 56 barrels of residual fuel oil.

Have a look to this page for more information about the amount of resources needed to produce electricity.

In any case it is clear that small energy savings do really count when looking into the bigger picture.

Proven ways to save electricity at home

If you are looking for ideas to save electricity at home, have a look to this YouTube video were we show some useful tips to reduce the electricity usage at home and decrease the electricity bill. 

How to save electricity at home
How to save
How to save
How to earn
How to earn


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