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

A 2026 Rivian R1S All-Terrain Dual Large (20in) draws 44.4 kWh per 100 miles per the EPA; at Idaho's 12.8¢/kWh residential rate that's $5.68 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: 64.6% 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 All-Terrain Dual Large (20in) charged at home in Idaho costs about $852/year in electricity, against about $2,403/year for the gas-car comparison. That's a savings of about $1,551 a year.

Cost of a full charge

A 2026 Rivian R1S All-Terrain Dual Large (20in) needs roughly 128.2 kWh to reach its EPA-rated 289-mile range, which runs about $16.41 at 12.8¢/kWh in Idaho.

How this compares nationally

This combination ranks 7,802 of 20,400 state/model pairs for cost savings against gas (1 is cheapest). The Rivian R1S All-Terrain Dual Large (20in) alone ranks 344 of 400 models for efficiency; Idaho alone ranks 3 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.

Line up a few Idaho 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 Dual Large (20in)'s cost in Idaho. Idaho is one of the cheapest states for home electricity — the guide to why the cost varies so much by state covers what drives that.