Most homes in the U.S. get "split-phase" power: two hot legs and a neutral. That gives you both 120 and 240 volts from the same panel.
How does my house get 120 and 240 volts?
The utility transformer delivers two hot legs that are each about 120 volts to the neutral and about 240 volts to each other. A single-pole breaker takes one leg for 120-volt circuits. A double-pole breaker takes both legs for 240 volts.
What uses 240 volts?
Electric ranges and ovens, dryers, water heaters, central AC and heat pumps, well pumps, hot tubs and most Level 2 EV chargers. These need their own circuits sized for the appliance.
How do I tell a 240-volt outlet?
240-volt receptacles are larger with differently shaped slots, for example 10-30 or 14-30 for dryers and 14-50 for ranges or EV charging. Plug shapes are made so you cannot plug a 120-volt device into a 240-volt outlet.
Why does an EV charger need 240 volts?
Level 1 charging on a 120-volt outlet adds only a few miles of range per hour. Level 2 on 240 volts charges several times faster. See EV charger basics.
Common questions
Do I have 240 volts in my house?
Almost all U.S. homes with modern service have 240 volts available at the panel. Whether a particular spot has a 240-volt outlet depends on the circuits installed.
General information for California homes under the California Electrical Code (based on the NEC). Local rules and inspectors can vary. Not a substitute for an on-site inspection. Never work inside a panel, at the meter or on live circuits.