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Power, voltage and current


1. What are Power, voltage and current

2. Power, voltage and current calculators

3. Plug in power meter

4. Energy conservation

4.1. Proven ways to save electricity at home

What are Power, voltage and current

Power (P) measures the rate at which energy is delivered or used by our household appliances. Power is equal to the voltage multiplied by the current.

P = V x I

Voltage (V) is the difference in electric potential between two points. Without going into technicalities, for some countries, household appliances and devices use 220 Vdc while others use 110 Vdc. Voltage is equal to power divided by current.

V = P / I

Current (I) measures the flow of electric charge through a material. Again, trying to keep it simple, the amount of current drawn is one of the two factors determining the energy/power used by a household appliance or device. Current is equal to power divided by voltage.

I = P / V

Voltage and current will let us determine the Power in Watts or Kilowatts. That knowledge already allows us to progress further with figuring out household appliances and devices’ electricity usage.

The following video explains what a Watt (W), Kilowatt (kW), and Kilowatt hour (kWh) are and how this knowledge can help us to find out our household appliances and devices’ electricity usage and electricity cost. 

Do not forget to enable the video captions, as the video caption contains the concepts and explanations.

What is a Kilowatt hour (kWh)

Power, voltage and current calculators

This calculator can be used to:

– Calculate Power (P) from Voltage (V) and Current (I).

– Calculate Wattage

-Calculate Watts

P = V x I


This calculator can be used to:

– Calculate Voltage (V) from Power (P) and Current (I).

V = P/ I


This calculator can be used to:

– Calculate Current (I) from Power (P) and Voltage (V).

-Calculate Amps

-Calculate Amperes

I = P / V


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

Plug in power meter

If you want to know an appliance or device’s exact power or electricity usage, using a plug-in power meter is best.

The image below will redirect you to the Amazon page, where you can look at the specifications of the power meter we use for our measurements.

plug in power meter

Our house appliances and devices like the washing machine, the dishwasher, the TV, or the printer are plugged into 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 time.

If you want to learn how to use a plug-in power meter to measure your electricity usage and cost, watch this YouTube video.

Plug in power meter

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 for your energy bills. 

And it also benefits the environment because conserving electricity prevents unnecessary waste of natural resources.

At the individual level, it may not look worth trying to save a few watts here or there. 

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


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

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 euros (or dollars, pounds, or any other currency) per kWh, we would collectively save nearly 6000 euros annually.

> 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.

Look at this page for more information about the resources needed to produce electricity.

In any case, small energy savings do count when looking into the bigger picture.

Proven ways to save electricity at home

Suppose you are looking for ideas to save electricity at home; look at this YouTube video. We show some useful tips for reducing electricity usage at home and decreasing 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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