Varies widely by state and other factors. I'm at around $0.18 for 1kWh when you look at the overall bill including generation, supply, and all other fees.

(My car averages 3.3 miles / kWh, so ~$0.055 / mile assuming 100% charge efficiency... I'm using a 120V outlet so it's probably 75-80% charge efficiency, pushing the cost to ~$0.068 / mile.)

Is using a 120V charger really only 80% charge efficiency? That would add another penny or two per mile to my cost.