What is the voltage of main electricity when it enters your house is?

There are different mains supply standards in different parts of the world.

-- It's AC almost everywhere in the world, rather than DC.

-- The frequency of the AC is either 50 Hz or 60 Hz everywhere. It's 60 Hz in all of North America.

-- Mains voltages include 400, 240, 230, 220, 127, 120, 115, 110, and 100 volts AC RMS

in various countries around the world.

In North America, the standard is 120v in the US and Canada, 127v in Mexico.