HomeUS → Japan
Do I need an adapter from the US to Japan?
No adapter needed for phone or laptop in Japan.
United States: Type A/B, 120 V, 60 Hz → Japan: Type A/B, 100 V, 50 / 60 Hz.
Dual voltage (100–240 V input) covers 100 V. Your Type A plug fits Japan's Type A sockets. Type B plugs only fit Type B sockets, which are uncommon in Japan; for those, pack an adapter for Type A sockets.
Dual voltage (100–240 V input) covers 100 V. Your Type A plug fits Japan's Type A sockets. Type B plugs only fit Type B sockets, which are uncommon in Japan; for those, pack an adapter for Type A sockets.
100 V is within what this device expects. At 100 V instead of 120 V it will run noticeably weaker. Your Type A plug fits Japan's Type A sockets. Type B plugs only fit Type B sockets, which are uncommon in Japan; for those, pack an adapter for Type A sockets. Japan uses both 50 Hz and 60 Hz depending on region.
100 V is in the same range as at home, so it works whether or not it is dual voltage. Your Type A plug fits Japan's Type A sockets. Type B plugs only fit Type B sockets, which are uncommon in Japan; for those, pack an adapter for Type A sockets. Japan uses both 50 Hz and 60 Hz depending on region.
100 V is in the same range as at home, so it works whether or not it is dual voltage. Your Type A plug fits Japan's Type A sockets. Type B plugs only fit Type B sockets, which are uncommon in Japan; for those, pack an adapter for Type A sockets. Japan uses both 50 Hz and 60 Hz depending on region.
100 V is within what this device expects. At 100 V instead of 120 V it will run noticeably weaker. Your Type A plug fits Japan's Type A sockets. Type B plugs only fit Type B sockets, which are uncommon in Japan; for those, pack an adapter for Type A sockets. Japan uses both 50 Hz and 60 Hz depending on region.
Why
Plug shape. The US uses Type A (two flat parallel pins) and Type B (two flat parallel pins and a round earth pin). Sockets in Japan 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. The US is 120 V; Japan is 100 V. Same voltage family, so everything you own will run. Adapter or converter?
Frequency. The US is 60 Hz; Japan is 50 / 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 the US to Japan?
No, not for a phone or laptop: your Type A plug fits Japan's Type A sockets. Type B plugs only fit Type B sockets, which are uncommon in Japan; for those, pack an adapter for Type A sockets.
Do I need a voltage converter from the US to Japan?
No. Both are in the same voltage range (120 V and 100 V), so single-voltage appliances work. A hair dryer will run differently, though: at 100 V instead of 120 V it will run noticeably weaker.
Will my US phone charger work in Japan?
Yes. Phone and laptop chargers are dual voltage (100–240 V). You do not even need an adapter.
What about the reverse trip, Japan to the US?
No adapter needed for your devices in the United States. Full Japan to US guide.