2026 Rivian R1S Dual Max (22in): home charging cost in Montana

A 2026 Rivian R1S Dual Max (22in) draws 39.9 kWh per 100 miles per the EPA; at Montana's 13.77¢/kWh residential rate that's $5.5 per 100 miles charged at home, versus $16.02 for a 25.5-mpg gas car covering the same distance. Charging at home costs a fraction of what gas would here: 65.7% less than gas per mile, here specifically.

Annual cost, at 15 thousands miles a year

Driving 15,000 miles a year — fueleconomy.gov's own default assumption — a 2026 Rivian R1S Dual Max (22in) charged at home in Montana costs about $825/year in electricity, against about $2,403/year for the gas-car comparison. That's a savings of about $1,578 a year.

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

A 2026 Rivian R1S Dual Max (22in) needs roughly 163.7 kWh to reach its EPA-rated 410-mile range, which runs about $22.55 at 13.77¢/kWh in Montana.

How this compares nationally

This combination ranks 6,956 of 20,400 state/model pairs for cost savings against gas (1 is cheapest). The Rivian R1S Dual Max (22in) alone ranks 265 of 400 models for efficiency; Montana alone ranks 10 of 51 states for electricity price.

Next step: home charger installation

The numbers above assume Level 2 home charging is already in place — the electrical work behind that is a real, separate cost that varies by panel, wiring, and local labor rates, not something this page's per-mile math includes.

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

Where these figures come from

The methodology guide names the exact EIA and EPA tables behind this page's numbers. Curious how Montana's 13.77¢/kWh compares? The guide to charging cost by state ranks every state side by side.