Electrical Sockets Types | The 15 Worldwide Standards, Explained

If you’ve ever stared at a wall outlet in a foreign hotel room, you know the feeling: your charger doesn’t fit, and you’re not sure why. The confusion is understandable — electrical sockets types vary dramatically around the world, and the differences go far beyond the shape of the holes. Voltage, frequency, grounding, and amperage all play a role in whether a plug will work safely. This guide breaks down the major standards so you know exactly what you’re looking at, whether you’re buying appliances for home or packing for a trip abroad.

How Many Electrical Socket Types Exist?

What matters more than the exact count is this: no single global standard exists. The same plug shape can carry different voltages in different countries, which is why plugging a device in is never just about whether it physically fits.

U.S. Electrical Sockets: Type A and Type B Explained

The United States runs on a 120-volt, 60-hertz supply, and the domestic standard is two receptacle types. The ungrounded Type A (NEMA 1-15) has two flat parallel prongs; the grounded Type B (NEMA 5-15) adds a round earth pin below them.

The most common outlet in a U.S. home is the NEMA 5-15, a 15-amp, 120-volt grounded receptacle. Other household configurations include the 5-20 (20 amps, 120 volts) and the 6-15 (15 amps, 240 volts), usually reserved for larger appliances like dryers or air conditioners.

In a standard U.S. outlet, one vertical prong connects to the hot wire and the other to neutral; on polarized plugs, one blade is intentionally longer so it can only insert one way. If you’re upgrading or replacing outlets around the house, a rundown of the best electrical sockets for home use can help you pick the right configuration for each room.

Major Plug Types Worldwide, A to N

Beyond North America, most of the world runs on 220–240-volt supplies, and the plug shapes reflect that. The table below covers the major standards and where you’ll find them.

Other types fill in the gaps: H (three flat pins) serves Israel, J (three round pins) serves Switzerland, K (three round pins) serves Denmark and Greenland, and M (three large round pins) is standard in South Africa. Each of these operates at 220–240 volts. Which type you need depends entirely on where you are — and where your device was made.

Why Plug Shape Isn’t Enough

The most common travel mistake is assuming a physical adapter changes voltage. It doesn’t. A shape adapter only lets your plug fit the socket; it does nothing about the electrical supply behind it. If you plug a 120-volt U.S. hairdryer into a 240-volt European outlet with just an adapter, you’ll likely fry the device.

Before plugging in abroad, check the device’s label. If it says “100–240V,” it’s dual-voltage and only needs a shape adapter. If it lists a single voltage, you need a voltage converter, not just an adapter. Also note that plug types don’t map to voltages 1:1 — countries sharing the same plug shape can still run different supply voltages, so the shape alone never guarantees compatibility.

One final distinction: a “plug” is the device-side connector, and the “socket” or “receptacle” is what’s built into the wall. They’re different halves of the same system, and both must match for a safe connection.