$27.38full charge
The Mustang Mach-E Premium (88 kWh) costs about $27.38 to charge fully at Rhode Island's average home rate of 28.29¢/kWh, including ~10% charging loss (96.8 kWh from the wall). That is $8.56 per 100 miles.
EIA residential average, Rhode Island, 2026-07 (latest in this book). No Rhode Island gasoline series, so this uses PADD 1A regular, week of Oct 5, 2026.
At 1,000 miles a month and 30 mpg, home charging costs $85.58 and the gas car costs $144.77. The EV saves $59.19 a month at $4.343/gal. Both miles and mpg are editable on the calculator.
The listed DC fast-charge time to 80% is 30 minutes at up to 150 kW. A full home charge is a different session. This page prices the energy from the wall, not how long a Level 2 charger takes.
This page uses the residential rate. Public fast-charging prices are a separate scenario and are not included.