The mains are somewhat nominal; 110,115,120 and 220,230,240. Depends on who you ask and where you are. I replaced a dedicated 20 amp GFCI receptacle last night in my house in Virgina Beach Virgina (approximately 20 feet of 12 gauge wire from breaker panel) and upon completion, my digital voltmeter read 114.8 volts.
Blacksmith