Type B vs Type O Plugs: Voltage & Amperage Differences & Compatibility
Type B is a 3-pin, grounded plug rated 15A at 100-127V, while Type O is a 3-pin, grounded plug rated 16A 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 O socket, and vice versa. Also see type A vs type J plug.
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Type B
|
Type O
|
|
|---|---|---|
| Standard | NEMA 5-15 | TIS 166-2549 |
| Pin Configuration | Two flat parallel pins plus round grounding pin (4.8mm diameter) | Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin) |
| Grounding | Grounded | Grounded |
| Pin Count | 3 | 3 |
| Amperage | 15A | 16A |
| Voltage Range | 100-127V | 220-240V |
Key Differences Between Type B and Type O
Here's how Type B and Type O compare, point by point.
- Grounding: Both Type B and Type O are grounded.
- Pin Size and Shape: Type B: Two flat parallel pins plus round grounding pin (4.8mm diameter). Type O: Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin).
- Application: Type B is typically used for heavy-duty appliances such as hair dryers, kettles, and heaters. Type O is typically used for heavy-duty appliances such as hair dryers, kettles, and heaters.
Type B and Type O Compatibility
Type B in Type O Sockets: Generally no. A Type B plug (Two flat parallel pins plus round grounding pin (4.8mm diameter)) does not fit a Type O socket (Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)) without a travel adapter.
Type O in Type B Sockets: Generally no. A Type O plug (Three round pins in triangular pattern (4.8mm diameter power pins, 4mm 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 O travel adapter. For a related pairing, see type H vs type N plug.
Does a Type B plug fit into a Type O socket?
Generally no. A Type B plug (Two flat parallel pins plus round grounding pin (4.8mm diameter)) does not fit a Type O socket (Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)) without a travel adapter. You might also want can i use a type C adapter for type L.
Are Type B and Type O plugs the same?
No. Type B follows the NEMA 5-15 standard and Type O follows TIS 166-2549 — they differ in voltage rating.
Which countries use Type B and Type O plugs?
Type B plugs are used in 54 countries, including American Samoa, Anguilla, Antigua and Barbuda, Aruba, Azores. Type O plugs are used in 1 countries, including Thailand. 1 countries use both, including Thailand.
How can you tell a Type B plug from a Type O plug?
A Type B plug has two flat parallel pins plus round grounding pin (4.8mm diameter), and is grounded. A Type O plug has three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin), and is grounded. The quickest tell is pin size and spacing — compare the two pin configurations above.