What it costs to charge a 2026 Rivian R1S Tri Max (22in) in Montana

In Montana, home electricity runs 13.77¢/kWh — put a 2026 Rivian R1S Tri Max (22in)'s EPA-rated 44.6 kWh/100mi against that and 100 miles costs $6.14, versus $16.02 for a gas car averaging 25.5 mpg. That works out to 61.7% cheaper per mile than gasoline in Montana — charging at home is much cheaper than gas here.

What a year of driving costs

Home charging this 2026 Rivian R1S Tri Max (22in) in Montana runs about $921 over fueleconomy.gov's default 15,000 annual miles, versus about $2,403 for the gasoline equivalent. Call it about $1,482 saved annually, at this mileage.

Filling up the 2026 Rivian R1S Tri Max (22in), in dollars

$22.77 — that's what Montana's 13.77¢/kWh rate puts on the 165.4 kWh a 2026 Rivian R1S Tri Max (22in) needs for its full 371-mile EPA range.

2026 Rivian R1S Tri Max (22in) in Montana, ranked

Among all 20,400 state-and-model combinations this site tracks, charging a 2026 Rivian R1S Tri Max (22in) in Montana ranks 10,060 for cost savings versus gas — 1 being the best deal nationally. Separately, the Rivian R1S Tri Max (22in) ranks 356 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.