Type B vs Type I Plugs: Voltage & Amperage Differences & Compatibility

Type B is a 3-pin, grounded plug rated 15A at 100-127V, while Type I is a 3-pin, grounded plug rated 10A at 220-240V. The two differ mainly in voltage, amperage and pin design, which is what decides compatibility — whether a Type B plug fits a Type I socket, and vice versa. You might also want type G vs type O plug.

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Type B power plug and wall socket
Type B
Type I power plug and wall socket
Type I
Standard NEMA 5-15 AS/NZS 3112
Pin Configuration Two flat parallel pins plus round grounding pin (4.8mm diameter) Two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin
Grounding Grounded Grounded
Pin Count 3 3
Amperage 15A 10A
Voltage Range 100-127V 220-240V

Key Differences Between Type B and Type I

Here's how Type B and Type I compare, point by point.

  • Grounding: Both Type B and Type I are grounded.
  • Pin Size and Shape: Type B: Two flat parallel pins plus round grounding pin (4.8mm diameter). Type I: Two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin.
  • Application: Type B is typically used for heavy-duty appliances such as hair dryers, kettles, and heaters. Type I is typically used for everyday household electronics and small appliances.

Type B and Type I Compatibility

Type B in Type I Sockets: Generally no. A Type B plug (Two flat parallel pins plus round grounding pin (4.8mm diameter)) does not fit a Type I socket (Two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin) without a travel adapter. Compare this with can i use a type A adapter for type G.

Type I in Type B Sockets: Generally no. A Type I plug (Two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin) does not fit a Type B socket (Two flat parallel pins plus round grounding pin (4.8mm diameter)) without a travel adapter.

If you're planning a trip, tell us which country you're visiting and we can confirm whether you need a Type B or Type I travel adapter.

Does a Type B plug fit into a Type I socket?

Generally no. A Type B plug (Two flat parallel pins plus round grounding pin (4.8mm diameter)) does not fit a Type I socket (Two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin) without a travel adapter.

Are Type B and Type I plugs the same?

No. Type B follows the NEMA 5-15 standard and Type I follows AS/NZS 3112 — they differ in voltage rating.

Which countries use Type B and Type I plugs?

Type B plugs are used in 54 countries, including American Samoa, Anguilla, Antigua and Barbuda, Aruba, Azores. Type I plugs are used in 24 countries, including American Samoa, Argentina, Australia, China, Christmas Island. 1 countries use both, including American Samoa.

How can you tell a Type B plug from a Type I plug?

A Type B plug has two flat parallel pins plus round grounding pin (4.8mm diameter), and is grounded. A Type I plug has two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin, and is grounded. The quickest tell is pin size and spacing — compare the two pin configurations above.