Charging a 2026 Rivian R1S Dual Standard (22in) at home in Montana

At Montana's residential electricity rate of 13.77¢/kWh, a 2026 Rivian R1S Dual Standard (22in) (rated 39.9 kWh per 100 miles by the EPA) costs $5.49 to drive 100 miles on home charging, against $16.02 for the same distance in a car averaging 25.5 mpg on gasoline at $4.085/gallon. That works out to 65.7% cheaper per mile than gasoline in Montana — charging at home costs a fraction of what gas would here.

Annual cost, at 15 thousands miles a year

Montana owners putting 15,000 annual miles on a 2026 Rivian R1S Dual Standard (22in) spend about $824 on home electricity, compared to about $2,403 a gas-car equivalent would spend on fuel. Call it about $1,579 saved annually, at this mileage.

Filling up the 2026 Rivian R1S Dual Standard (22in), in dollars

At Montana's rate, fully covering this 2026 Rivian R1S Dual Standard (22in)'s 270-mile EPA range costs about $14.83 (107.7 kWh) — the energy the EPA test actually used, not the battery's rated size.

How this compares nationally

Among all 20,400 state-and-model combinations this site tracks, charging a 2026 Rivian R1S Dual Standard (22in) in Montana ranks 6,957 for cost savings versus gas — 1 being the best deal nationally. Separately, the Rivian R1S Dual Standard (22in) ranks 262 of 400 EV models for raw efficiency, and Montana ranks 10 of 51 for cheapest residential electricity.

Before you install a home charger in Montana

Everything above is the per-mile and per-year cost once a home charger exists — getting one installed is a separate electrical job whose price depends on your panel and wiring, not the state average used here.

Line up a few Montana electrician quotes for Level 2 install before you commit either way.

More on how this number was built

The methodology guide names the exact EIA and EPA tables behind this page's numbers. Montana's 13.77¢/kWh rate ranks 10 of 51 states; the state rate guide lays out the full spread.