Charging a 2027 Rivian R1S Premium (20in) at home in Idaho

At Idaho's residential electricity rate of 12.8¢/kWh, a 2027 Rivian R1S Premium (20in) (rated 42.9 kWh per 100 miles by the EPA) costs $5.49 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. That works out to 65.7% cheaper per mile than gasoline in Idaho — charging at home costs a fraction of what gas would here.

2027 Rivian R1S Premium (20in): yearly cost in Idaho

Idaho owners putting 15,000 annual miles on a 2027 Rivian R1S Premium (20in) spend about $823 on home electricity, compared to about $2,403 a gas-car equivalent would spend on fuel. Call it about $1,580 saved annually, at this mileage.

What one full charge costs

At Idaho's rate, fully covering this 2027 Rivian R1S Premium (20in)'s 300-mile EPA range costs about $16.46 (128.6 kWh) — the energy the EPA test actually used, not the battery's rated size.

Where this ranks

Among all 20,400 state-and-model combinations this site tracks, charging a 2027 Rivian R1S Premium (20in) in Idaho ranks 6,921 for cost savings versus gas — 1 being the best deal nationally. Separately, the Rivian R1S Premium (20in) ranks 314 of 400 EV models for raw efficiency, and Idaho ranks 3 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 Idaho 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. 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.