Why Different Countries Have Different Standard Voltages?

There are a few electronic devices that work anywhere in the world without experiencing any power issues.

When you read this statement, your first reaction might be:

why is that a big deal meme

Yes, some devices do function without any glitches, regardless of the place and country where they’re being used, but why should the place (where the device is being used) matter at all?

To answer that, we’ll have to dig a little deeper into the world of appliances and electricity. Let’s start with the basics.

What is Voltage?

You’ve surely seen a number of warning signs, especially on electricity poles, that advise you to keep away from them, along with informing you that there are ‘440 Volts – Danger!’ present there.

danger sign

Image Source: Flickr.com

What do ‘Volts’ actually signify?

Voltage (measured in Volts) is the measure of the potential difference between two points in an electrical field. To put this in perspective, consider a stream of water coming from a water tank. The amount of water coming out is the electric charge, the water flow is the electric current and the pressure at which the water flows represents voltage.

Now, you might be asking, “What’s that got to do with the question posed at the beginning of the article?” To which I would say…

everything meme

You see, to make an electronic device (say, a laptop) work, you need to provide it with electric current. That’s precisely what you do when you plug your appliance into a wall socket: a potential difference is established between the wall socket and the laptop charger, allowing current to flow to the laptop.

Note that the value of standard operating voltage in countries typically goes into the hundreds. For instance, in the United States, the standard voltage is around 120 Volts (at 60 Hertz), whereas in India, it’s around 230 Volts (at 50 Hertz); other countries may also have a wide range of different voltages. This brings us to…

Why do different countries have different standard voltages?

There’s a good reason behind that too. Consider India (230 Volts) and the United States (120 Volts) as an example. If the voltage is low, the amount of current passing through to produce the same amount of power is more. Therefore, there’s a lower risk of getting injured if one happens to come in physical contact with an unprotected live wire (as the voltage is low), but there are greater energy losses (as the current is high, resistance is high too). In countries having higher voltages, energy losses are lower, but the risk of sustaining injuries is much higher.

Voltage requirements for electronic devices

As you just saw, the value of standard voltage goes into the hundreds, such as 120 Volts or 230 Volts. However, the voltage requirement of individual components of an electronic device (say, a laptop) is much lower. In fact, it’s typically not more than 20-30 Volts for newer laptops. That being said, how do laptops downscale that high voltage to such low values to fit their requirements? And how do certain electronic machines work almost anywhere in the world?

Switch Mode Power Supply


If either your laptop charger or smartphone charger is nearby, pick it up and read the tiny words printed on its body. You will almost certainly see an ‘Input Voltage’ Rating value and an ‘Output Voltage’ rating value.

Below are some images of the charger for my own mobile phone and laptop.

Mobile & Computer charger

Do you notice the huge difference between the input and output voltage values? How does that work out?

Electronic devices (that take power directly from a power outlet) typically contain a small internal device called an SMPS that performs down-scaling of voltages. If you are a tech enthusiast, then you might know SMPS by different names, such as Switch Mode Power Supply, Switched Power Supply or simply Switcher. It’s basically an electrical component that consists of a regulator to convert high incoming voltage (say, 230 Volts) to a lower output voltage (20 Volts).

Manufacturers often market their products as having ‘built-in stabilizers’, which is, in fact, not completely accurate. The term ‘built-in stabilizer’ is actually a misnomer in the context of electronic devices, as most electronic devices don’t need stabilizers, thanks to the small internal component (SMPS) inside them. This is also why these electronic devices work in different countries without any problem.

in built stabilizer meme

Now you know why you can tote your laptop anywhere, whether you’re traveling to New York, London, Paris, Moscow, Sydney or Mumbai, without ever worrying whether it’s going to stop working in the low-voltage areas or blow up in the high-voltage ones!


  1. World standards
  2. Gizmodo
  3. How To Geek
  4. School of Engineering
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About the Author:

Ashish is a Science graduate (Bachelor of Science) from Punjabi University (India). He spends a lot of time watching movies, and an awful lot more time discussing them. He likes Harry Potter and the Avengers, and obsesses over how thoroughly Science dictates every aspect of life… in this universe, at least.

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