Guam Electricity Guide

Guam uses Type A (two flat parallel pins) and Type B (two flat parallel pins plus a round grounding pin) power outlets — exactly the same as the United States mainland. If you are travelling from the US or Canada, your plugs will fit Guam outlets with no adapter required.

Type A outlets are the most common in hotels and guesthouses. Type B (3-pin, grounded) outlets are also widely available. Both accept US-standard plugs without any modification.

Guam's electrical supply runs at 110 volts (V) at 60 Hz — the same standard as the United States. This is important for visitors from countries that use 220–240V systems (most of Asia outside Japan, and most of Europe).

However, the vast majority of modern consumer electronics — smartphone chargers, laptop power supplies, camera chargers, and travel hair dryers — are dual-voltage (100–240V, 50–60Hz). Check the label on your charger or power supply: if it lists '100–240V', it will work safely in Guam with just a plug adapter and no voltage converter needed.

Single-voltage 220V appliances (some older hair dryers, electric shavers, or kitchen devices) will not work safely in Guam without a step-up voltage converter. These are heavy and rarely worth bringing — rent or buy locally if needed.

🇺🇸 United States / 🇨🇦 Canada: No adapter needed. Your plugs and voltage are identical to Guam.

🇯🇵 Japan: No adapter needed. Japan uses Type A plugs at 100V — Guam's 110V is close enough that all Japanese devices work safely. Most modern Japanese electronics are already designed for the 100–240V range.

🇰🇷 South Korea: Adapter needed. Korea uses Type C and F plugs at 220V/60Hz. You need a US Type A/B adapter. Check that your chargers are dual-voltage (100–240V) — most modern Korean phone chargers and laptop supplies are. For Korean hair dryers and single-voltage appliances, a voltage converter is also required.

🇹🇼 Taiwan: Adapter situation is mixed. Taiwan uses Type A plugs at 110V/60Hz — same voltage and frequency as Guam! Most Taiwanese plugs will physically fit Type A Guam outlets, though a Type B adapter (for grounded sockets) may occasionally be needed. No voltage converter is required.

🇨🇳 China / 🇦🇺 Australia / 🇬🇧 UK / Europe: Adapter needed. These countries use different plug types and mostly 220–240V. You need a US Type A/B adapter. Most modern chargers (100–240V) won't need a voltage converter.

Most hotel rooms in Guam have a limited number of US-standard outlets — typically 2–4 per room. Bringing a compact US-style power strip (multi-outlet adapter) is useful for charging multiple devices simultaneously, especially for families or travellers with multiple electronics.

USB charging ports are available in newer hotel rooms and some common areas. Many Tumon resort hotels have upgraded rooms with USB-A and USB-C ports built into bedside panels.

If you forget your adapter, hotel front desks in Guam often have spare adapters for loan or purchase. Electronics and travel accessory shops in Micronesia Mall and GPO also sell adapters at reasonable prices.