Guam power adapters - what plugs are used in Guam?

Guamanian power outlet

What adapter do I need for Guam?

You'll need to use a Type B plug adapter [3] for Guam if your plug doesn't fit into a Guamanian power outlet.

The type of power adapter, power converter or charger that you'll need when visiting Guam all depend on the voltage and type of device that you're attempting to charge with a Guamanian power outlet. If you're not sure which voltage your device uses then read the section about how can you tell if you have a single voltage or dual voltage device before going any further.

  • If you're from the US visiting Guam then you will not require a power converter or an adapter. One suggestion however is to pack a USB travel power adapter as it allows you to charge multiple devices using only one charger.
  • If your device can run on 110 volts or is dual voltage and your plug fits in a Guamanian power outlet then it should work in Guam without needing anything else.
  • If your device is 110 volts or is dual voltage but your plug doesn't fit in a Guamanian power outlet you'll need a suitable plug adapter for Guam such a Type B plug adapter [3]. Please be aware that a plug adapter for Guam (or power adapter) is designed to change the shape of the plug on your device to fit into a plug outlet found in Guam, but but is unable to change the voltage from 110 volts to a different voltage.
  • If your device doesn't run on 110 volts and isn't dual voltage you will also need a power converter for Guam to convert the voltage from 110 volts to the correct voltage for your device. You'll still need to bring along a suitable plug adapter for Guam if your power converter doesn't have the correct Type B plug adapter.
  • If you simply need to power one or more USB devices such as cell phones or tablets then a USB travel power adapter will be more suited and it should be dual voltage, but make sure that you bring one which includes a Type B plug adapter otherwise you will also need to use a suitable plug adapter for Guam.
  • Increased use of a phone during a trip will create an extra demand on the battery, we suggest bringing a portable charger [4] if you want to recharge your cellphone battery whilst visiting an unfamiliar location.

Warning: If your device won't handle 110 volts you run a risk of an electrical fire hazard, blowing a fuse or damage to your device. Before attempting to use your device in Guam please read the instruction manual to ensure safe operation.

Guam power adapters

Power adapters for Guam

Various voltages and sockets can all be confusing when planning to travel to a different country, especially for the first time traveller. With only a handful of different types of standards being used throughout the world this article tells you exactly what you'll need in advance to power your electronics in Guam. This page has links to useful instructions demonstrating exactly how to power your devices when you are in Guam using their Type B or A Guamanian 110 volt 60Hz wall outlets. You'll find power sockets differ regionally so please read the power adapters page for a complete list of countries.

What is the best power adapter for Guam?

The best power adapter for Guam will be a Type B plug adapter [3] which allows you to use any 110 volt device or appliance.

What is the best power adapter for Guam?

What is a power adapter?

A power adapter for Guam is a small and lightweight plastic adapter that allows a power plug from a foreign country to correctly fit into a power outlet in Guam.

Also known as: an electrical adapter, plug adapter, travel adapter, electrical adaptor, mains travel adapter or power adaptor [5].

Do I need a plug adapter for Guam?

It will depend on where you are travelling from and the type of plug you are attempting to use.

What does a power adapter for Guam do?

A power adapter allows visitors from another location to use their electrical appliances in Guam by altering the shape of the plug from one type to another.

Do I need a power adapter for Guam if I'm visiting from the US?

A US plug does not need an adapter as it will fit into a Guamanian power outlet.

Can a power adapter change the voltage from a Guamanian power outlet?

Power adapters only adapt the shape of a plug to fit into a 110 volt Guamanian power outlet and doesn't convert the power to a higher voltage. Should you need to safely use any 220, 230 or 240 volt appliance you also need to bring a more expensive step up power converter along with the correct type of power adapter.

Guam power outlets and plug sockets

What plug sockets are used in Guam?

Type A and B power outlets

What plug sockets are used in Guam?

There are two types of power supply used in Guam, these are type B and A with the primary power supply being type B:

  • Plug Type A - The power outlet, also called a type A power outlet, is recognised by two thin slots adjacent to each other for live and neutral.
  • Plug Type B - You can recognise the power outlet by 2 thin slots adjacent to each other with a hole below for the slightly longer earthed pin.

Do US plugs work in Guam?

Yes, an American plug will work in Guam without a power converter or plug adapter.

What is the frequency used in Guam?

The frequency of the current used in a Guamanian power outlet is 60 Hz.

Is a Guamanian power outlet the same as the US?

An American plug will fit into power outlets used in Guam, the frequency and voltage range are both the identical to the US.

How do I use a 220 volt appliance in Guam?

A step up power converter will allow you to use a 220V appliance in Guam.

Is the voltage in Guam the same as in the US?

120 volts is used in America but the voltage from a Guamanian power outlet is 110 volts. Even though these are similar check the voltage on your US appliance or charger supports voltage fluctuations between 100-127 volts or that it can handle dual voltage.

Do I need a power bank for Guam?

USB power bank

Do I need a power bank for Guam?

It is always advised to bring a power bank to recharge mobiles whilst on a trip.

  • For many the thought of being offline can cause anxiety, especially when being needed abroad. Whilst travelling increased use of smart phones for taking photos, storing calendars, sat nav, social network sharing and staying entertained can syphon off power towards the end of the day. A flat smart phone battery could potentially leave you in an unknown location without adequate power to make an emergency call or being able to use a GPS app to find your way back to hotel. By packing a portable charger [4] for Guam lowers the risk as it means you can keep your cell phone powered on the go.
  • A 10,000mAh power bank [4] can store enough electricity to power over three full charging cycles and a 20,000mAh power bank [9] should keep a typical smart phone charged for roughly seven days. A mAh rating (or milli ampere-hours) shows the capacity of a battery and gives an indication of the number of cycles the power bank can do, and a higher number is more suitable for travellers.
  • If your laptop supports USB-C charging then packing a portable charger for a laptop [10] marked with PD (power delivery) that supplies at least 20Wh can be used to recharge your laptop.
  • Be aware that some airlines prohibit portable chargers on an aircraft that supply 100 Wh of power or more and must be kept in carry-on luggage only.
  • Consumer power banks won't work with high wattage items, although a rechargeable hair dryer [7] or gas hair straighteners [8] are designed for travelling.
How well do solar battery chargers work in Guam?

Solar backpacks are ideal in hot countries

How well do solar battery chargers work in Guam?

The sunshine in Guam should be adequate enough to charge solar power bank [12] dependably, however it will need to be exposed to strong daylight to produce enough power for a single charge cycle. It may prove inconvenient to constantly unpack a solar power bank then wait for it to recharge in sunny spells.

  • The much larger solar cells used on a solar backpack [11] will give the bag the ability to generate more power within a faster period of time, making them ideal for the climate in Guam.
  • A device that has been directly plugged into the USB port of a backpack should gradually top up the power during sunny spells in Guam, however might be inconvenient to have it constantly tethered in the bag during the day if it is to be used frequently. A regular power bank [4] plugged in a solar backpack can be continuously powered up inside the bag during sunlight, afterwards you can power up the phone from the power bank at any time without being attached to the bag.
  • Although the climate in Guam is suitable for solar power, a bag should have a solar cell efficiency of 22% or more, be able to generate at least 6 watts of energy and can be used with a power bank of 10,000mAH or stronger. The flexible and durable solar panels used in solar powered bags are designed to survive scratches and bending, unlike normal solid solar panels. They are found in backpack, messenger and rucksack styles making them perfect for domestic, work and travel.


Guam chargers

What is a USB travel power charger?

A USB travel charger is a dual voltage charger with interchangeable plugs and multiple USB ports, suitable for charging multiple USB powered devices when travelling abroad.

What USB charger do I need for Guam?

When travelling to multiple countries the best travel adapter for Guam to buy is a multiple USB port adapter which includes swappable plugs like a 4 port USB travel charger [13]. There are two types of wall outlets in Guam (B and A) and using a travel charger like this ensures that you are covered for type A.

As these types of chargers come with interchangeable plugs and handle 100 - 240 volts will mean that you can travel to over 100 countries in North America, Europe, Asia and Africa simply by switching the plugs over. If your model of device can support Fast Charge then you will benefit from faster recharging times by using one of these types of power chargers and additional compatibility with more power hungry devices. This means you can power more than one device at the same time without needing to bring multiple travel chargers or occupying additional power outlets. Only bringing a single lightweight USB travel charger will also keep the overall size and weight down, making it perfect to store in hand baggage while travelling. Because of their space saving versatility these types of power chargers can be used when you return home so when you're not on holiday they can sit under your bedside table charging multiple phones, tablets and speakers and using just a single plug socket.

For those travelling often we recommend searching for this type of versatile power charger online. The power charger illustrated here is the 4 Port USB Wall Charger [13] which has been tested successfully for recharging multiple USB devices in numerous different countries.

What USB charger do I need for Guam?

Why use a travel USB charger for Guam?

  • Most travel USB chargers include multiple USB charger ports, this means that you should only need to bring a single charger to charge all your devices. Instead of bringing 4 individual power chargers you only need to pack a single 4 port USB wall charger and power up to 4 separate devices, thereby cutting down on the size and weight of your baggage.
  • All travel USB power chargers should include interchangeable plug heads for different power outlet types. This is ideal if visiting other countries which will probably use a different standard to Guam.
  • Good chargers are lightweight, compact and rugged; perfect for the rigors of travel instead of than risking bringing a domestic charger which might be hard to replace or repair in Guam.
  • USB travel chargers can accept both the 110 volts used in Guam power outlets and different voltage standards across the world.
  • It's possible that some hotels in Guam only have one power outlet, by using a travel charger with multiple USB ports means you can share out the single power supply with family or other traveler instead of waiting to charge one device at a time.
  • Due to their flexible nature they take the worry out of travelling to an unknown country as they are guaranteed to work almost anywhere on the planet.
  • Power outlets found in airports can be scant and demand for charging multiple devices before a flight can be high, so a USB travel charger with multiple ports and the capability to fast charge is perect.
  • The power grid in some countries can be unstable, a travel charger allows for unexpected spikes and will help prevent damage to any devices attached to it. Attempting to repair an overloaded mobile phone in Guam might prove inconvenient and costly.
  • Premium USB travel chargers will also incorporate power outlet strips to power low wattage domestic appliances such as laptops, however these are unsuitable for high wattage appliances such as hair dryers or clothes irons. Read the guide on using travel appliances in Guam for advice and guidelines on the best power adapter for using a high powered appliances in a Guamanian power outlet.
  • Certain mobile phones could require more than the normal 500 mA produced from a standard 5 volt USB power adapter to charge or provide fast charge. Ensure that the USB power adapter can support fast charging should any of your devices need extra power.
  • On returning home travel USB power chargers can still be used by charging multiple mobile phones on a daily basis using only a single power outlet.

What is the best USB charger for Guam?

The is the most compact option for travellers from any country who only have USB devices, but for visitors also wanting to use their domestic plugs these power converters provide larger but more versatile solutions. All 3 power adapters offer surge protection which can be useful for visitors of regions with unstable power grids to prevent damage to any connected devices from voltage spikes. These power adapters come with interchangeable type C, I and G plugs covering Europe, America, Australia, United Kingdom, Japan, China and over 150 destinations:

  • BESTEK Portable International Travel Voltage Converter - The BESTEK international travel converter has 4 USB charging ports with 3 AC power outlets and is the most popular portable power converter for travellers originating from America going to Guam using 3 pinned type B US plug sockets.
  • ORICO Traveling Outlet Surge Protector Power Strip - Likewise having 4 USB ports but only 2 AC power outlets the travel adapter from Orico is also aimed at travellers from North America using type B plugs. This is a more cost effective alternative to the BESTEK with only 1 less AC outlet at almost half the price.
  • BESTEK International USB Travel Power Strip - This power strip has 2 AC outlets but offers 5 USB charging ports. This versatile power strip is compatible with both American plugs and popular plug types A, D,E/F, G, H, I, L and N making it perfect for a majority of travellers from around the world visiting Guam.

Power converters for Guam

What is a power converter?

Power converters enable you to use a 220, 230 or 240 volt electrical appliance with a 110 volt Guamanian power outlet.

Also known as: electrical converter, electrical transformer, voltage converter, power transformer or voltage transformer.

What is the difference between a power converter and a power adapter for Guam?

An expensive and heavy power converter [14] converts a 110 volt Guamanian power outlet to work with a non-110 volt appliance, whereas a more lightweight and smaller power adapter (or plug adapter) will change the shape of the plug on your device to fit into a power outlet found in Guam.

Do I need a power converter for Guam?

When you are travelling to Guam from another country please ensure that the device will accept a 110 volt power supply.

  • You need a step up power converter [15] if you are travelling to Guam from a country that uses 220-240 volts and your appliance or device won't support 110 volts. Read our world power outlets guide to discover which voltage is used in your country.
  • You shouldn't need a power converter if you are already using either a single voltage device that works with 110 volts or one that is dual voltage.
  • Electrical devices which originate from a country which use a higher voltage (such as 230 volts) and used in a 110 volt outlet either take longer to charge or simply won't power up. If your device charges slowly or does not power up when visiting Guam from a different region check that it can be used with a 110 volt Guamanian power outlet otherwise you will need to use a step up power converter [15].
  • You shouldn't need a power converter if you wish to power a smaller electrical device such as a cell phone as these are typically designed for international use and dual voltage, but you should always check the device for dual voltage support prior to your journey.
  • For powering high wattage appliances or generate heat (such as hair dryers or curling irons) then you will need to use a much larger higher wattage heavy duty power converter [16].
  • Buying a robust lightweight dual voltage travel appliance will be more cost effective and practical than trying to bring a much heavier high wattage power converter in order to use your existing domestic appliance in Guam.
  • Read our guides on using clothes irons, curling irons, hair dryers and flat irons in Guam which includes guides on affordable dual voltage alternatives.

Do I need a power converter if I'm visiting Guam from America?

You won't need to use a power converter as the voltage in Guam is in the same 100-120 volt range as the US.

What kind of converter do I need for Guam?

You will need to use a step up power converter [15] in order to use any 220-240 volt appliance with a 110 volt Guamanian power outlet.

What is the difference between a transformer and a converter?

Voltage converter

What is the difference between a transformer and a converter?

Converters and transformers are both used to change one voltage to another, but this ambiguity can cause confusion as their purposes are different:

  • Power converters are designed for simple electrical appliances which typically generate heat or use motors such as clothes irons, shavers or hair dryers. Transformers are designed for more complex electronic items such as televisions or games consoles.
  • Buying a power converter is cheaper than buying a power transformer.
  • Power transformers are larger and heavier making them more suited for permanent residential use; for example an expat wishing to use an imported television would need to use a transformer for this purpose.
  • Power converters are more suitable for travellers wishing to bring domestic appliances abroad such as hair dryers or flat irons. However, it is more practical and cost effective to purchase a dual voltage appliance designed for travel rather than a heavier power converter.
  • Power converters are suitable for 2 pin ungrounded appliances, it could be harder to find a converter if you want to use a grounded 3 pin appliance.
  • Transformers can be used constantly however it is recommended that converters are used for no longer than a couple of hours at a time.
  • Shops may sell transformers under the name of converters, for the purposes this guide we will be referring to both converters and transformers as converters.

How to convert 110 volts to 220 volts

  1. Use a step up power converter [15] to allow you to use 220, 230 and 240 volt appliances with a 110 volt Guamanian power outlet.
  2. If the power converter doesn't include the correct shaped plug then it will also be necessary to plug in the power cord from the power converter into a power adapter for Guam before plugging that into a Guamanian power outlet.
  3. Some power converters include the ability to perform both step up and step down voltage conversions, therefore it may be necessary to manually switch the converter to output the voltage from 220-240v.
  4. Plug your appliance into the converter and turn the power on, your 220-240 volt appliance can now be used with a 110 volt Guamanian power outlet.

What voltage is used in Guam?

Guam uses 110 volts in their standard power outlets.

What voltage is my appliance?

Single voltage hair dryer

What voltage is my appliance?

The best way to tell if your device is dual voltage is to look for either a sticker or numbers printed on the supplied charger or on the unit itself, typically on the rear or near to where the power cord goes. This location might vary depending on the make or model of your unit but could also be written on the box or in the instruction manual.

  • Single voltage devices might have a specific number - such as 240V.
  • Single voltage devices could also have a small voltage range (around 20 volts) with a dash to accomodate small voltage fluctuations - such as 100-120V.
  • Dual voltage devices will say a large voltage range separated with a slash - such as 100/240V.

What can I connect to a Guamanian power outlet

Travel appliances that can connect to a Guamanian power outlet

Beats Pill speakers which can connect to a Guamanian power outlet

Jabra Bluetooth speakers which are compatible with a Guamanian power outlet

Mobile phones which work with the Guamanian power outlet

Apple iPhones which can be connected to a Guamanian power outlet

Samsung Galaxy phones that can connect to a Guamanian power outlet

A list of Amazon Kindle tablets which can connect to a Guamanian power outlet

A list of Apple iPads which are compatible with a Guamanian power outlet


We endeavor to ensure all details on this page are correct and relevant to travelers visiting Guam, if you wish to contribute any useful information or feedback please email For more comprehensive technical details visit the Wikipedia page on AC power plugs and sockets [18].

  1. - Guam country Wiki page.
  2. - International Electrotechnical Commission World Plugs
  3. Type B plug adapter - Allows appliances to connect to Type B power outlets without converting voltage.
  4. Portable charger - A power bank is a portable charger which can recharge USB powered devices such as mobile phones and tablets on the go.
  5. - power adaptor
  6. - WikiPedia - Mains electricity by country
  7. Rechargeable hair dryer - Rechargeable battery powered blow dryer suitable for travelling.
  8. Gas hair straighteners - Cordless ceramic hair straighteners powered by gas cartridges.
  9. 20,000mAh portable charger - High capacity 20000mAh high-speed portable USB charger suitable for charging mobile phones and some tablets for several days.
  10. USB-C PD power bank - Power Delivery charger suitable for charging laptops with USB-C support.
  11. Solar backpack - A solar backpack will charge USB devices or an internal power bank when left in sunlight.
  12. Solar power bank - Portable power bank with solar cells which can recharge when placed in sunlight and power any USB powered device.
  13. 4 Port USB Wall Charger - A universal USB charger capable of charging up to 4 USB devices with swappable international adapters.
  14. Power converter - A step up step down power converter converts 110-120 volts up to 220-240 volts and 220-240 volts down to 110-120 Volts.
  15. Step up power converter - A step up power converter allows a 220-240 volt appliance to be used in a 100-120 volt power outlet.
  16. Heavy duty power converter - A 5000 watt heavy duty step up and step down power converter used to convert voltages for domestic appliances, power tools, televisions, heating appliances and motors.
  17. Step down power converter - A step down power converter allows a 100-120 volt appliance to be used in a 220-240 volt power outlet.
  18. - AC power plugs and sockets