PlugVoltage

United States to Japan Power Adapter Guide

United States runs 120⁠V and Japan runs 100⁠V. Your plug shape is compatible; confirm the exact input range, frequency and grounding before use.

United States and Japan share a broad voltage zone; that does not prove that every appliance rating matches. Confirm the exact voltage and frequency on its label.

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

SpecUnited StatesJapan
Voltage120⁠V100⁠V
Frequency60⁠Hz50/60⁠Hz
Plug typesType A/BType A/B

Your United States devices in Japan

Hair Dryer Check Label MacBook Pro Charger (USB-C Power Adapter) Check Rating CPAP Machine Check Label iPhone Charger Check Rating
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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Safety check: a plug adapter only changes plug shape. It does not convert voltage, so confirm your device label before buying.

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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?

For the typical United States single-voltage model: check its exact label and manufacturer instructions first; the shared voltage zone is not proof of compatibility. Japan is 100⁠V. Confirm frequency and any voltage selector before connecting.

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.