Montana home charging cost for the 2026 Rivian R1S Dual Max (20in)

A 2026 Rivian R1S Dual Max (20in) draws 42 kWh per 100 miles per the EPA; at Montana's 13.77¢/kWh residential rate that's $5.78 per 100 miles charged at home, versus $16.02 for a 25.5-mpg gas car covering the same distance. Charging at home is much cheaper than gas here: 63.9% less than gas per mile, here specifically.

2026 Rivian R1S Dual Max (20in): yearly cost in Montana

At fueleconomy.gov's default of 15,000 annual miles, the 2026 Rivian R1S Dual Max (20in) costs roughly $867 a year to charge at home in Montana, against roughly $2,403 a year for an equivalent gas car. That's a savings of about $1,536 a year.

What one full charge costs

Covering the 2026 Rivian R1S Dual Max (20in)'s EPA-rated 380-mile range takes about 159.5 kWh, which costs about $21.96 at Montana's residential rate — figured from the EPA's own combined range and consumption numbers, not the pack's nameplate capacity.

Where this ranks

This combination ranks 8,403 of 20,400 state/model pairs for cost savings against gas (1 is cheapest). The Rivian R1S Dual Max (20in) alone ranks 298 of 400 models for efficiency; Montana alone ranks 10 of 51 states for electricity price.

Getting set up to charge a 2026 Rivian R1S Dual Max (20in) at home

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. At 13.77¢/kWh, Montana sits in the middle of the national range — the guide to why charging cost varies by state shows where.