2027 Rivian R1S Premium (20in): home charging cost in Washington
A 2027 Rivian R1S Premium (20in) draws 42.9 kWh per 100 miles per the EPA; at Washington's 14.35¢/kWh residential rate that's $6.15 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: 61.6% less than gas per mile, here specifically.
2027 Rivian R1S Premium (20in): yearly cost in Washington
Driving 15,000 miles a year — fueleconomy.gov's own default assumption — a 2027 Rivian R1S Premium (20in) charged at home in Washington costs about $923/year in electricity, against about $2,403/year for the gas-car comparison. That's a savings of about $1,480 a year.
Cost of a full charge
A 2027 Rivian R1S Premium (20in) needs roughly 128.6 kWh to reach its EPA-rated 300-mile range, which runs about $18.46 at 14.35¢/kWh in Washington.
How this compares nationally
This combination ranks 10,132 of 20,400 state/model pairs for cost savings against gas (1 is cheapest). The Rivian R1S Premium (20in) alone ranks 314 of 400 models for efficiency; Washington alone ranks 15 of 51 states for electricity price.
Getting set up to charge a 2027 Rivian R1S Premium (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.
Line up a few Washington electrician quotes for Level 2 install before you commit either way.
Where these figures come from
Every figure on this page traces to a named EIA or EPA dataset — see the methodology guide. Washington's 14.35¢/kWh rate ranks 15 of 51 states; the state rate guide lays out the full spread.