In North America, household 110–120V circuits typically use these plug styles:

• NEMA 1-15 (2-prong): Two flat blades, no ground. Common on older or double-insulated devices.
• NEMA 5-15 (3-prong): Two flat blades plus a round ground pin. This is the most common grounded plug for everyday devices.

Most standard wall outlets are matching 15A receptacles for these plugs. Some circuits use 20A outlets that accept a NEMA 5-20 plug (with a T-shaped neutral slot). Always match your device’s plug to the outlet and check the device label for voltage and amperage. If you need to adapt shape or extend reach, you’ll find plug adapters, outlets, and extension cords in our Home Improvement categories.

In the U.S. and Canada, people often say 110V and 120V interchangeably. The electrical system is designed around a nominal 120V, but actual voltage can vary, so 110V is a common shorthand. The outlets themselves are the same style (typically NEMA 5-15 for 3-prong and NEMA 1-15 for 2-prong).

• Device labels: Many products list 110–120V and are designed for normal line variation.
• Frequency: Standard is 60 Hz in North America.
• Travel note: For 220–240V regions, you may need a plug adapter and possibly a voltage converter.

When in doubt, check your device’s nameplate. You’ll find plug adapters and voltage converters under Plug Adapters and Power Transformers.

Most 110–120V plugs in North America have flat blades and may include a ground pin:

• 2-prong (NEMA 1-15): Two parallel flat blades. Often polarized, with one blade wider to match the outlet’s neutral slot.
• 3-prong (NEMA 5-15): Two flat blades plus a round or U-shaped ground pin below. This is common for grounded devices.
• 20A variant (NEMA 5-20): Looks similar but the neutral blade or outlet slot has a T shape.

Outlets may be tamper-resistant with internal shutters for safety, which is common in newer homes. If your plug doesn’t match the outlet or you’re traveling, a plug adapter can help with shape—just be sure the voltage is compatible with your device.

Results can vary by device design. Many products labeled 110–120V operate normally across typical household voltage ranges. However:

• Electronics with switching power supplies: Often tolerate a wide range and may perform similarly; always check the label.
• Motors or heating elements: May run a bit slower or cooler on lower voltage, potentially affecting performance.
• Strictly 120V-only devices: Could underperform or fail to start properly if voltage is significantly lower.

Always read the device nameplate for voltage and wattage. If you’re using equipment across regions with different mains (for example, 220–240V), consider a suitable voltage converter in addition to any plug adapter. When unsure, consulting a qualified electrician can help you choose the safest setup.

It depends on what you’re trying to do:

• Plug adapter: Changes the shape of the plug to fit a different outlet style. It doesn’t change voltage.
• Voltage converter/transformer: Changes the voltage (for example, 220V to 110V or vice versa). Choose one with enough wattage for your device.

Check your device label. If it says 100–240V, 50/60 Hz, you typically only need a plug adapter when traveling. If it lists a single voltage (like 120V only), you may need a converter in countries with 220–240V power. You’ll find both options under Plug Adapters and Power Transformers. Always match wattage and avoid exceeding a converter’s rating.