Charging a 2026 Rivian R1S Quad Max (20in AT) at home in Montana

In Montana, home electricity runs 13.77¢/kWh — put a 2026 Rivian R1S Quad Max (20in AT)'s EPA-rated 50.1 kWh/100mi against that and 100 miles costs $6.9, versus $16.02 for a gas car averaging 25.5 mpg. That works out to 56.9% cheaper per mile than gasoline in Montana — charging at home is much cheaper than gas here.

What a year of driving costs

Montana owners putting 15,000 annual miles on a 2026 Rivian R1S Quad Max (20in AT) spend about $1,035 on home electricity, compared to about $2,403 a gas-car equivalent would spend on fuel. Call it about $1,368 saved annually, at this mileage.

What one full charge costs

At Montana's rate, fully covering this 2026 Rivian R1S Quad Max (20in AT)'s 325-mile EPA range costs about $22.42 (162.8 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 Quad Max (20in AT) in Montana ranks 12,811 for cost savings versus gas — 1 being the best deal nationally. Separately, the Rivian R1S Quad Max (20in AT) ranks 392 of 400 EV models for raw efficiency, and Montana ranks 10 of 51 for cheapest residential electricity.

Next step: home charger installation

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.

Ask a licensed Montana electrician to quote the install before this math becomes a real decision.

More on how this number was built

Every figure on this page traces to a named EIA or EPA dataset — see the methodology guide. At 13.77¢/kWh, Montana sits in the middle of the national range — the guide to why charging cost varies by state shows where.