$17.64full charge
The EX90 PLUS_TWIN (107 kWh) costs about $17.64 to charge fully at Montana's average home rate of 14.99¢/kWh, including ~10% charging loss (117.7 kWh from the wall). That is $5.92 per 100 miles.
EIA residential average, Montana, 2026-07 (latest in this book). No Montana gasoline series, so this uses PADD 4 regular, week of Oct 5, 2026.
At 1,000 miles a month and 30 mpg, home charging costs $59.21 and the gas car costs $147.23. The EV saves $88.03 a month at $4.417/gal. Both miles and mpg are editable on the calculator.
The listed DC fast-charge time to 80% is 30 minutes at up to 250 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.