Using United States Electronics in Japan

United States runs 120⁠V and Japan runs 100⁠V. Your plug shape is compatible; dual-voltage gear works as-is.

United States and Japan share the same voltage zone, so most devices only need a plug adapter for the socket shape.

United States (120⁠V) vs Japan (100⁠V) at a glance

Spec	United States	Japan
Voltage	120⁠V	100⁠V
Frequency	60⁠Hz	50/60⁠Hz
Plug types	Type A/B	Type A/B

Your United States devices in Japan

Hair Dryer Yes MacBook Pro Charger (USB-C Power Adapter) Yes CPAP Machine Yes iPhone Charger Yes

Next step

What to do next

Check one device in JapanUse your exact device label for Japan, not just the route average.Build a Japan trip packSave several devices, adapter needs, and converter/no-go warnings together.Adapter vs converterAvoid the common mistake: plug shape does not change voltage.

The adapter we recommend

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Get a United States→Japan adapter

Safety check: a plug adapter only changes plug shape. It does not convert voltage, so confirm your device label before buying.

Shopping links never change the safety verdict.

Best travel adapters for Japan →

FAQ

Do United States plugs work in Japan?

Often yes — the plug shapes are compatible. But check the voltage before plugging single-voltage devices in.

Will my United States hair dryer work in Japan?

The voltage matches, so a dual-voltage or compatible model is fine — you may still need a plug adapter.

Is the voltage different between United States and Japan?

United States is 120V and Japan is 100V. They are in the same voltage zone.

Power outlets in Japan · Adapter vs converter

Guidance only — not professional electrical advice. Always confirm against your device's label before plugging in. Local wiring (especially in hotels and older buildings) can vary.