The United States primarily uses 110-120 volts (VAC) at 60 Hertz (Hz) for its electrical supply, while most other countries use a higher voltage and lower frequency of 220–240 volts at 50 Hz. This difference exists because electrical standards were established independently by different regions in the late 19th and early 20th centuries, with early investments in equipment making global standardization difficult.
When traveling to another country, you need to understand how the different voltage/frequency levels can affect your devices. If you’re traveling within the United States, or to Canada, Mexico, Central America, the Caribbean, northern South America, or Japan, then you can plug in your devices as you do now. These countries all use two-pronged Type A, and three-pronged Type B plugs on a standard 110-120 VAC / 60 Hz network. If you’re not traveling within those countries, you will need an adapter and/or converter.
A travel adapter changes the shape of the electrical plug to fit a foreign wall socket, while a travel converter changes the electrical voltage of the outlet to match the needs of a non-dual-voltage appliance. You only need a converter for single-voltage appliances like many hair dryers or curling irons; most modern electronics like phone and laptop chargers are dual-voltage (100-240V) and only need an adapter.
Note: It's best to use dual-voltage devices for travel because they are designed to work with the different voltage standards (e.g., 120V and 240V) found in various countries, eliminating the need for voltage converters and reducing the risk of damage or fire.
Travel Adapter
Function: Adapts the physical shape of your device's plug to fit the socket in a foreign country.
When to Use: You need an adapter for most small electronics, such as cell phone chargers, tablet chargers, and laptop chargers, as they are dual-voltage.
What It Does Not Do: It does not change the electrical voltage.
Note: Worldwide, there are 15 different plug types, so knowing what they each look like and what countries use them is a must before you set out on your international travel. Many plug types are interchangeable, similar to how you can use a two-pronged Type A device in a three-pronged Type B socket. Because of this, we recommend inquiring about the country’s or region’s adapters, rather than the specific adapter type.
Travel Converter
Function: Converts the voltage of the wall outlet to match your appliance's voltage requirement.
When to Use: You need a converter if your device is not dual-voltage and is designed for a specific voltage, such as 110-125V devices used in 220-240V countries. Examples include some hair straighteners, shavers, and steamers.
What It Does Not Do: The converter itself does not change the physical shape of the plug, and must be used in conjunction with a travel adapter.
Notes:
If using a single-voltage device, it is critical to determine the necessary wattage requirements of the electronic devices being used. To ensure a travel converter meets wattage requirements, you must first find the wattage of your specific electronic device and then choose a converter with a maximum wattage rating that is 2 to 3 times higher. Using a converter with insufficient wattage can damage your device and the converter.
If the label lists only voltage (V) and amperage (A), calculate the wattage using this formula: Watts = Volts x Amps. For example, if your device is 120V and 5A, its wattage is 600W.
How to Determine What You Need
Check Your Device's Label: Look for the voltage range printed on the device or its charger.
Dual-Voltage (e.g., 100-240V or 100/240V): If your device is dual-voltage, you only need a travel adapter to change the plug shape.
Single-Voltage (e.g., 110-125V): If your device is single-voltage, you will need a travel converter to change the voltage, in addition to an adapter.
What Happens If I Don't Use A Converter?
Verifying voltage and frequency is critical for ensuring the safety, reliability, and proper function of electrical and electronic systems. Incorrect voltage or frequency can cause equipment damage and safety hazards, including electrical shock and fire.
Recommendations
Travel Adapter
Multiple companies offer a wide variety of travel adapters, from versatile all-in-one units to smaller, budget-friendly options. An individual adapter is a small, single-country plug that only works in regions with a specific type of socket, while a universal adapter is a larger, multi-region device with interchangeable or sliding prongs to fit various plug types worldwide. The main trade-off is portability versus versatility; individual adapters are more compact, whereas universal adapters are bulkier but convenient for travelers visiting multiple countries.
Highly-rated brands that produce travel adapters include Anker, Epicka, Ceptics, and TESSAN. I have had good luck with Ceptics and will base my recommendations on their products.
Individual Travel Adapters
With all the different plug types, it's impossible to make a single recommendation for an individual adapters. Use this page to find the appropriate individual adapter, or choose a set of adapters.
Universal Travel Adapters
If your international travels take you to more than one region, I highly recommend investing in a universal adapter that can be used throughout your trip and across the world—they also work with either grounded or ungrounded plugs, and grounded or ungrounded outlets. (This video explains grounding well.) Use this page to search all Ceptics universal travel adapters. The universal adapter I use is this one.
Travel Converters
With all the different plug types and wattage requirements, it's impossible to make a single recommendation for an individual converter. Use this page to find the appropriate individual converter with the needed adapter(s).
SWadAPt Travel Adapters & Converters
The Ceptics SWadAPt attachments are interchangeable plug heads designed for use with specific Ceptics travel power adapters and/or converters. These attachments allow a traveler to use one compatible adapter body in over 200 countries worldwide by simply swapping the plug head for the correct type. Use this page to find SWadAPt compatible devices including travel adapters, travel converters, plug sets, and extension cords.
For Further Reading
Ceptics Website: Do I need a voltage converter?
Ceptics Website: Voltage Transformers vs Converters