120v is not actual voltage in the US. Depending on time of day and your house and area, that can be anywhere from 105 to 120volts actual.
120 volts is very much the actual voltage in the US, and is specified by ANSI C84.1. Range A in the standard (or what is the normal voltage) specifies a service voltage of 120 volts plus or minus 5%, so an in-spec unloaded residential voltage is 114-126 volts. There is a range B that allows service voltages to drop as low as 110 at the very lowest, but events causing voltage to be in range B must be limited in extent, frequency, and duration. In other words if they occur frequently the utility is required to correct things to get the voltages back to the 114-126 volt spec. There is no allowance for a service voltage of 105 volts.
I think the lowest unloaded voltage I’ve ever seen has been around 117 volts. Normally it’s plus or minus a couple volts from 120, as it should be.
Now, it’s certainly possible to see the
loaded circuit voltage drop below 110, if you have a heavy load and a lot of voltage drop, but 110 is an abnormal voltage to see at an outlet in the US barring this. In the spec the absolute minimum voltage anything in your house should have when
fully loaded with maximum NEC allowed voltage drops and the minimum of the range B service voltage (which again is not normal) is 104 volts. And this is very, very much an edge case. Devices are likely to start having issues here, especially motors.
Sorry, got on my soapbox there, a pet peeve of mine when people say the standard voltage in the US is not 120 volts, because that very much is the standard voltage in the US.