Type B vs Type I Plugs: Differences & Compatibility

Type B vs Type I plugs are not compatible: an adapter is needed in both directions. 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. Also see how does the amperage rating of a type J plug compare to a type L plug.

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Not Compatible Adapter needed in both directions Compatible Adapters	Type B	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. Also see will a type G plug work in a type O socket without an adapter.

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. Also see how the NEMA 1-15 standard for type A compares to BS 1363 for type G.

Type B vs Type I plug comparison: Type B and Type I wall sockets and plugs side by side, with the verdict and which way each plug fits, a specification table, key differences and how to tell them apart. Verdict: Not Compatible. — Type B vs Type I Plug: Differences and Compatibility (Infographic)

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 United States of America, Japan, Vietnam, Thailand, Canada. Type I plugs are used in 24 countries, including Australia, China, Argentina, New Zealand, Fiji. 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.