A voltage converter and/or voltage transformer is a must-have for certain electrical situations. If you don’t know anything about voltage converters and transformers, the range of options can be a bit overwhelming.

First things first: a voltage converter and a voltage transformer are not the same thing! They have different purposes. In this article, we’ll explain whether you need a voltage converter or a voltage transformer for certain common situations. We’ll also tell you how to choose the power rating for the converter or transformer.

How to Buy Voltage Converters and/or Transformers for Travel

1. Understand World Voltages

To understand your voltage needs, especially if you’re traveling, you should familiarize yourself with world voltages. While the exact voltage in any given location can vary within the range, the range itself in each country is set in stone.

Source: Wikipedia. Image in public domain.

Source: Wikipedia. Image in public domain.


  • Orange: 100 – 127V AC, 60Hz
  • Light Blue: 220 – 240V AC, 50Hz
  • Dark Blue: 220 – 240V AC, 60Hz
  • Brown: 100 – 127V AC, 50 Hz

2. Sort Your Stuff Into Electrical Appliances and Electronic Devices


An electrical appliance is something with an electric heating element—e.g., a curling iron. An electronic device is something with chips in it—e.g., a cell phone or a laptop. An electronic device can ONLY operate on a transformer. An electrical appliance can operate on a voltage converter OR a transformer.

Set aside your electronic devices. They will require a voltage transformer.

3. Check To See If Your Electrical Appliances Are Single Voltage

Many modern appliances (like hair dryers, hair straighteners, etc.) can run on both 110-120V and 220-240V. Others can only run on 110-120V. Sort your appliances by whether they are single or dual voltage.

4. Make A List Of Everything You’ll Need To Plug Into A Voltage Converter

Whether or not it will happen in reality, you should plan on having all of your single-voltage appliances plugged in at the same time. That way, you can calculate the total power-handling capability that you’ll need in a voltage converter.

Remember, you just sorted your stuff into electronic devices and electrical appliances. After that, you sorted your electrical appliances into single and dual voltage. There’s no need to include dual voltage appliances in this list, because you won’t need to plug them into a voltage converter—unless you want to simplify things with just one adapter plug. I.e., since your dual-voltage appliances can easily run off the voltage which your voltage converter will supply, you can include them in this total list if you want (since that will allow you to get just one adapter plug).

Look at each single-voltage appliance that you intend to plug into your voltage converter. Find the wattage rating (W) of each appliance. This is a measure of how much power the device will require. Add up the wattage ratings of all the appliances you’re taking with you. This is the total wattage which you might need at one time on your trip. But this is NOT the wattage rating that you should look for in a voltage converter.

5. Multiply Your Total Wattage Needed by 3x

Some types of higher-powered appliances will cause a gigantic temporary spike in power consumption when they’re turned on. While it’s unlikely that you’ll bring your dad’s table saw with you to France, it’s still safest to buy a voltage converter that offers 3x the maximum power handling capacity that you think you’ll need. The extra power-handling in the transformer won’t hurt your devices.

6. Get a Voltage Transformer for your Electronics

If you need to power electronics on your trip, you’ll need a voltage transformer. Remember, electronic devices can NOT be powered off a voltage converter—only off a transformer.

Alternately, you can just buy a voltage transformer, since both electronics and electrical appliances can run off it.

International outlet shapes

7. Get Plug Adapters for your Voltage Converter And/Or Voltage Transformer

Converting voltage isn’t the only thing you need to do. Different countries use different outlets and plugs. You need to make sure you have the right adapter to run your equipment in the country you’re going to. Plug adapters don’t convert voltage; they simply get you from one mechanical connection format to another.

This chart from World Standards explains the plug type which you will need in each country. If you are taking along a voltage converter and a voltage transformer, you’ll need an adapter plug for each one. Remember, you can power electrical appliances off a voltage converter OR a voltage transformer, but electronic devices can ONLY run off a voltage transformer. If you’re running everything off a voltage transformer, you’ll only need one adapter plug.

voltage-converter-home-useHow to Buy Voltage Converters And/Or Transformers for Domestic Use

Buying a voltage converter for home use is similar to buying one for travel. While you don’t have to worry about voltages in different countries, you do need to know a few things about the appliances you’re going to plug into the voltage converter.

A) To Power Your Appliances At Home

8. Check Appliance Voltage

This is a no-brainer. Look at the specifications tag on the appliance and see what type of voltage it needs. Some appliances can run on 110-120V or 220-240V. If that’s the case with your appliance, you’re in luck! You don’t need a voltage converter to run it in the US.

If your appliance only runs on 220-240V, you will need a voltage converter to run it off a 110V outlet. This is often the case with high-powered appliances like stoves and power tools. If you don’t have a 220V outlet, you will need a voltage converter to run these appliances in the US.

9. Check Appliance Wattage

This is critical. You cannot run a high-powered appliance through a voltage converter that doesn’t handle that much power. If you do, the appliance either won’t work, or you’ll damage the voltage converter, possibly creating a fire hazard.

10. Multiply Appliance Wattage by 3x

High-powered appliances, particularly power tools, often consume a huge spike in power when they’re turned on. This is totally fine—as long as your voltage converter can handle it. To be safe, you should ALWAYS use a voltage converter that is rated for at least 3x the normal wattage listed on your appliance.

11. Look At The Outlet(s) You’ll Be Using

Some voltage converters require 2 out-of-phase 110V outlets to run off of. The Quick220 Voltage Converter is one such device. You simply plug its two input cords into 2 standard US outlets that are wired out of phase and do not have GFIs (ground fault interrupters) on their circuits.

12. Check Your Appliance’s Power Cord

In the US, there are several possible plug types on a 220V appliance. You should examine your appliance’s power cord and see what type of plug it requires. If this plug does not match the 220V outlet on your voltage converter, you will need a plug adapter.


Photo courtesy of HeatSync Labs. Licensed under Creative Commons 2.0 SA.

Photo courtesy of HeatSync Labs. Licensed under Creative Commons 2.0 SA.

B) To Power Your Odd-Voltage Electronic Devices At Home

In the rare event that you have a mismatch at home between your country’s voltage and the voltage rating of an electronic device, you will need a voltage transformer. You can NOT run an electronic device off a voltage converter—only off a transformer.

13. Gather All Devices Which You Will Need to Power Off the Voltage Transformer

Again, you need to total up the wattage (power) requirements for all the devices which will get power through the transformer.

14. Multiply Total Wattage Needed by 3x

This ensures that your voltage transformer can handle the spike in power consumption which some devices use on startup.

15. Get the Appropriate Adapter(s) for your Electronics

You may need an adapter for each device which you hope to plug into the voltage transformer. How many adapters you need will depend on 1) how many devices you need to plug in at one time, and 2) how many output outlets your voltage transformer has.

16. Get An Appropriate Power Strip If Necessary

If you need to power more devices than you have outlets on your transformer, you will need a power strip. There’s a major caveat here, though: MAKE SURE you get a power strip that’s rated for the output voltage of your voltage transformer—not the input voltage!

Wrap Up

Buying a voltage converter or voltage transformer doesn’t have to be hard. We hope this guide has helped you understand exactly what you need. If you have any questions, don’t hesitate to contact us and tell us about your specific application.