HomeJapan → US
Do I need an adapter from Japan to US?
No adapter needed for phone or laptop in United States.
Japan: Type A/B, 100 V, 50 / 60 Hz → United States: Type A/B, 120 V, 60 Hz.
Dual voltage (100–240 V input) covers 120 V. Your Type A plug fits United States's Type A socket.
Dual voltage (100–240 V input) covers 120 V. Your Type A plug fits United States's Type A socket.
120 V is within what this device expects. Your Type A plug fits United States's Type A socket.
120 V is within what this device expects. Your Type A plug fits United States's Type A socket.
Dual voltage (100–240 V input) covers 120 V. Your Type A plug fits United States's Type A socket.
120 V is within what this device expects. Your Type A plug fits United States's Type A socket.
Why
Plug shape. Japan uses Type A (two flat parallel pins) and Type B (two flat parallel pins and a round earth pin). United States sockets are Type A (two flat parallel pins) and Type B (two flat parallel pins and a round earth pin). They are compatible, so no adapter is needed.
Voltage. Japan is 100 V; United States is 120 V. Same voltage family, so everything you own will run.
Frequency. Japan is 50 / 60 Hz; United States is 60 Hz. No change to worry about.
Japan: Japan runs on 100 V nationwide, lower than anywhere else. The frequency is split: 50 Hz in eastern Japan (Tokyo, Yokohama, Sapporo, Sendai) and 60 Hz in western Japan (Osaka, Kyoto, Nagoya, Hiroshima, Fukuoka). Sockets are mostly ungrounded Type A; grounded Type B sockets are uncommon outside newer buildings, so a US three-pin plug may need a 3-to-2 adapter. Japanese Type A pins are the same width, so a polarised US plug (one wide blade) may not fit an older Japanese socket.
Frequently asked questions
Do I need an adapter from Japan to US?
No. Your Type A plug fits United States's Type A sockets.
Do I need a voltage converter from Japan to US?
No. Both countries are in the same voltage band (100 V and 120 V), so even single-voltage appliances work.
Will my Japan phone charger work in US?
Yes. Phone and laptop chargers are dual voltage (100–240 V). You do not even need an adapter.
What about the reverse trip, US to Japan?
See the US to Japan guide.