Type I vs Type O Plugs: Differences & Compatibility

Type I vs Type O plugs are not compatible: an adapter is needed in both directions. Type I is a 3-pin, grounded plug rated 10A 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 I plug fits a Type O socket, and vice versa. Compare this with type A plugs run on 100-127V while type E plugs run on 220-240V.

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Not Compatible Adapter needed in both directions Compatible Adapters	Type I	Type O
Standard	AS/NZS 3112	TIS 166-2549
Pin Configuration	Two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin	Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)
Grounding	Grounded	Grounded
Pin Count	3	3
Amperage	10A	16A
Voltage Range	220-240V	220-240V

Key Differences Between Type I and Type O

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

Grounding: Both Type I and Type O are grounded.
Pin Size and Shape: Type I: Two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin. Type O: Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin).
Application: Type I 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 I and Type O Compatibility

Type I in Type O 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 O socket (Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)) without a travel adapter. Also see is it safe to use a type E device on a type N socket.

Type O in Type I 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 I socket (Two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin) without a travel adapter. Also see comparing type B and type G plugs for international travel.

If you're planning a trip, tell us which country you're visiting and we can confirm whether you need a Type I or Type O travel adapter.

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

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

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 O socket (Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)) without a travel adapter.

Are Type I and Type O plugs the same?

No. Type I follows the AS/NZS 3112 standard and Type O follows TIS 166-2549 — they differ in pin design.

Which countries use Type I and Type O plugs?

Type I plugs are used in 24 countries, including Australia, China, Argentina, New Zealand, Fiji. Type O plugs are used in 1 countries, including Thailand.

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

A Type I plug has two angled flat pins (8mm long, 6.5mm wide, 30 degree angle) plus vertical grounding pin, 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.