Type M vs Type O Plugs: Differences & Compatibility

Type M vs Type O plugs are not compatible: an adapter is needed in both directions. 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. For a related pairing, see type F plugs run on 220-240V while type L plugs run on 220-240V.

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Not Compatible Adapter needed in both directions Compatible Adapters	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. Next, check will a type G plug work in a type K socket without an adapter.

Type M vs Type O plug comparison: Type M and Type O 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 M vs Type O Plug: Differences and Compatibility (Infographic)

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. You might also want what adapter converts a type B plug to a type E socket.

Which countries use Type M and Type O plugs?

Type M plugs are used in 9 countries, including India, South Africa, Nepal, Namibia, Mozambique. 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.