Type M vs Type O Plugs: Amperage & Pin Design Differences & Compatibility
Type M is a 3-pin, grounded plug rated 15A at 220-240V, while Type O is a 3-pin, grounded plug rated 16A at 220-240V. The two differ mainly in amperage and pin design, which is what decides compatibility — whether a Type M plug fits a Type O socket, and vice versa. Compare this with type B vs type H plug.
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Type M
|
Type O
|
|
|---|---|---|
| Standard | BS 546 (15A) | TIS 166-2549 |
| Pin Configuration | Three large round pins in triangular pattern (earth 8.7mm diameter, live/neutral 7.1mm 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 | 220-240V | 220-240V |
Key Differences Between Type M and Type O
Here's how Type M and Type O compare, point by point.
- Grounding: Both Type M and Type O are grounded.
- Pin Size and Shape: Type M: Three large round pins in triangular pattern (earth 8.7mm diameter, live/neutral 7.1mm diameter). Type O: Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin).
- Application: Type M 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 M and Type O Compatibility
Type M in Type O Sockets: Generally no. A Type M plug (Three large round pins in triangular pattern (earth 8.7mm diameter, live/neutral 7.1mm 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 M 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 M socket (Three large round pins in triangular pattern (earth 8.7mm diameter, live/neutral 7.1mm 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 M or Type O travel adapter.
Does a Type M plug fit into a Type O socket?
Generally no. A Type M plug (Three large round pins in triangular pattern (earth 8.7mm diameter, live/neutral 7.1mm 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.
Are Type M and Type O plugs the same?
No. Type M follows the BS 546 (15A) standard and Type O follows TIS 166-2549 — they differ in pin design. Compare this with type C vs type O plug.
Which countries use Type M and Type O plugs?
Type M plugs are used in 9 countries, including Andaman & Nicobar Islands, Eswatini, India, Lakshadweep, Lesotho. Type O plugs are used in 1 countries, including Thailand.
How can you tell a Type M plug from a Type O plug?
A Type M plug has three large round pins in triangular pattern (earth 8.7mm diameter, live/neutral 7.1mm 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. Also see does a type F plug fit a type L socket.