United States of America (US) USA Power Plugs, Wall Sockets & Electrical Outlets
In United States of America (US) USA, power plugs and sockets (electrical outlets) of Type A (NEMA 1-15, two flat parallel pins, ungrounded) and Type B (NEMA 5-15, two flat parallel pins plus round grounding pin, grounded) are used. Wall sockets run at 120V and 60Hz. Check if you need a travel adapter, electrical adapter or voltage converter before travelling to United States of America (US) USA.
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United States of America (US) USA uses:
What Plug Type Does United States of America (US) USA Use?
The United States of America (US) USA power plug comes in two standard forms: Type A and Type B. Type A is the familiar two-pin, ungrounded plug used for smaller electronics like lamps and phone chargers, while Type B adds a round grounding pin and is required for larger appliances, computers, and power tools. Both plug types are part of the NEMA standard and are used interchangeably throughout the country, often within the same building.
Do All Sockets in United States of America (US) USA Look the Same?
Not every electrical outlet in the country looks identical, though they share a common footprint. Standard outlets accept the flat parallel pins of a Type A plug, while grounded outlets also include a third opening for the round grounding pin found on a Type B 3-pin plug. Because Type B outlets accept both plug types, most modern sockets are backward compatible, so a simple two-pin plug top will fit into either style of receptacle without issue.
- Type A (NEMA 1-15): two flat parallel pins, ungrounded, rated 15A at 100-127V
- Type B (NEMA 5-15): two flat parallel pins plus a round grounding pin, rated 15A at 100-127V
Electrical Standards in United States of America (US) USA: Voltage, Frequency & Plug Type
Voltage and Frequency in United States of America (US) USA
The electrical system runs on 120V at a frequency of 60Hz. This is lower than the 220-240V standard used in many other parts of the world, so travelers from those regions should check whether their devices can handle 120V before plugging in. Most modern electronics, including phone and laptop chargers, are dual-voltage and can operate safely on this supply without a converter.
Grounding is an important safety feature built into the Type B outlet, as the longer grounding pin connects before the power pins make contact, reducing the risk of shock. Type B outlets are required by code in kitchens, bathrooms, outdoor areas, and garages, while ungrounded Type A plugs remain acceptable for smaller, low-power devices that don't need a grounded connection.
Frequently Asked Questions
If your home country uses Type A or Type B plugs, such as Canada or Mexico, you won't need an adapter. Travelers from countries using other plug standards will need an adapter to fit either the two-pin Type A or three-pin Type B sockets used throughout the country.
The electrical supply operates at 120V and 60Hz. This is standard across the country for homes, offices, and most commercial buildings.
Many sockets are grounded through the Type B outlet, which includes a round grounding pin alongside the two flat power pins. Older buildings or smaller appliances may still use ungrounded Type A outlets, which lack this grounding pin.
Yes, most phone chargers are designed to handle a range of voltages and will work fine on the 120V, 60Hz supply without a converter. You'll just need a plug adapter if your phone charger's plug top doesn't match the Type A or Type B outlets used locally.
