Type D vs Type O Plugs: Differences & Compatibility

Type D vs Type O plugs are not compatible: an adapter is needed in both directions. Type D is a 3-pin, grounded plug rated 5A 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 D plug fits a Type O socket, and vice versa. You might also want packing an adapter for a trip that has both type H and type M sockets.

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Not Compatible Adapter needed in both directions Compatible Adapters	Type D	Type O
Standard	BS 546	TIS 166-2549
Pin Configuration	Three large round pins in triangular pattern (ground pin 7.1mm, live/neutral 5.1mm diameter)	Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)
Grounding	Grounded	Grounded
Pin Count	3	3
Amperage	5A	16A
Voltage Range	220-240V	220-240V

Key Differences Between Type D and Type O

Here's how Type D and Type O compare, point by point.

Grounding: Both Type D and Type O are grounded.
Pin Size and Shape: Type D: Three large round pins in triangular pattern (ground pin 7.1mm, live/neutral 5.1mm diameter). Type O: Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin).
Application: Type D is typically used for everyday household electronics and small appliances. Type O is typically used for heavy-duty appliances such as hair dryers, kettles, and heaters.

Type D and Type O Compatibility

Type D in Type O Sockets: Generally no. A Type D plug (Three large round pins in triangular pattern (ground pin 7.1mm, live/neutral 5.1mm 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 D 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 D socket (Three large round pins in triangular pattern (ground pin 7.1mm, live/neutral 5.1mm 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 D or Type O travel adapter. You might also want how the pin configuration of a type F plug differs from a type M plug.

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

Does a Type D plug fit into a Type O socket?

Generally no. A Type D plug (Three large round pins in triangular pattern (ground pin 7.1mm, live/neutral 5.1mm 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 D and Type O plugs the same?

No. Type D follows the BS 546 standard and Type O follows TIS 166-2549 — they differ in pin design. For a related pairing, see type C plugs run on 220-240V while type D plugs run on 220-240V.

Which countries use Type D and Type O plugs?

Type D plugs are used in 31 countries, including India, Maldives, Nepal, Tanzania, Jordan. Type O plugs are used in 1 countries, including Thailand.

How can you tell a Type D plug from a Type O plug?

A Type D plug has three large round pins in triangular pattern (ground pin 7.1mm, live/neutral 5.1mm 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.