The voltages listed here are the “nominal” figures reported to be in use at most residential or commercial sites in the country or area named. Most electrical power systems are prone to slight variations in voltage due to demand or other factors. The electric power frequency is shown in the number of hertz (cycles per second). All systems described here use alternating current (AC).

Where 110-220 is indicated, voltage varies depending on location within the country.

Finally, we've only included information that is likely to be relevant for travelers. Just about all the countries listed here have higher voltage lines available for heavy duty appliances (not to mention commercial or industrial applications).