2026 Rivian R1S All-Terrain Performance Dual Large (20in): home charging cost in Montana

At Montana's residential electricity rate of 13.77¢/kWh, a 2026 Rivian R1S All-Terrain Performance Dual Large (20in) (rated 44.4 kWh per 100 miles by the EPA) costs $6.11 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. Charging at home is much cheaper than gas here: 61.9% less than gas per mile, here specifically.

What a year of driving costs

Driving 15,000 miles a year — fueleconomy.gov's own default assumption — a 2026 Rivian R1S All-Terrain Performance Dual Large (20in) charged at home in Montana costs about $916/year in electricity, against about $2,403/year for the gas-car comparison. That's a savings of about $1,487 a year.

Cost of a full charge

A 2026 Rivian R1S All-Terrain Performance Dual Large (20in) needs roughly 128.2 kWh to reach its EPA-rated 289-mile range, which runs about $17.65 at 13.77¢/kWh in Montana.

2026 Rivian R1S All-Terrain Performance Dual Large (20in) in Montana, ranked

This combination ranks 9,904 of 20,400 state/model pairs for cost savings against gas (1 is cheapest). The Rivian R1S All-Terrain Performance Dual Large (20in) alone ranks 345 of 400 models for efficiency; Montana alone ranks 10 of 51 states for electricity price.

Before you install a home charger in Montana

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.

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

Where these figures come from

See the methodology guide for exactly which EIA and EPA figures feed 2026 Rivian R1S All-Terrain Performance Dual Large (20in)'s cost in Montana. Montana's 13.77¢/kWh rate ranks 10 of 51 states; the state rate guide lays out the full spread.