Scales the annual-dollar line; the per-mile comparison doesn't depend on it. The URL keeps your scenario.
Home: —
Supercharger: —
Gap: —
On those miles/year: —
Efficiency: this site's per-model EPA wall-side dataset (charging losses included — add nothing). Home rate default: EIA EPM 5.6.A, July 2026. Supercharger pricing is set per station and can vary by hour and membership — which is why that field starts empty.
Supercharger price
You enter it — no default; check the app
Home rate
State June-2026 EIA average, or your own
Efficiency
Per-model EPA wall-side (losses included)
Why no default
Pricing is per-station, can vary by hour
Output
¢/mile both ways + annual gap on your miles
What it can't do
Predict any station's price for you
Why this number
No website can honestly quote a Supercharger price: rates vary by station, by hour and by membership tier, and are published in no dataset — so this calculator leaves that field empty and asks for the per-kWh price from your own Tesla app before comparing it to your home electricity rate. With both prices and your model entered, it applies that model’s real wall-side efficiency to show cost per mile on each option — and by how much one beats the other in your numbers, not a national guess.
Supercharger pricing is a per-station fact, not a national one — so this page refuses to guess it, and instead does exact arithmetic on the number in your app.
Home charging per mile, model by model
Home charging cost per mile for tracked EV models at the July 2026 state-average extremes and the labeled US average
*17¢ = EIA 2025 annual US average (July 2026 monthly: 18.31¢). The Supercharger column is missing on purpose: there is no honest national number to print — the calculator above takes yours.
Why no site can quote Supercharger prices honestly
Pricing is set per station and can flex by time of day and membership tier — idle fees and per-kWh rates differ for members and non-members — with no published national dataset behind any of it. Any calculator showing a fixed default Supercharger price is guessing; this one asks for your number instead.
The per-mile math
Cost per mile is price per kWh × kWh per 100 miles ÷ 100 — identical arithmetic on both sides, two different prices. The efficiency figure is your model’s EPA wall-side number (charging losses already inside), applied to both options so neither side gets a flattering generic figure.
When home wins, and by how much
Home wins whenever your home rate is below the Supercharger price you entered, and the win scales with that gap times your model’s appetite — a thirstier EV widens the dollar difference per mile. Superchargers can still win on convenience or a genuinely cheap station; this tool prices the trade-off, it doesn’t settle it.
How we calculated this
Home cost per mile = kWh/100 mi ÷ 100 × home rate;Supercharger cost per mile = kWh/100 mi ÷ 100 × the per-kWh price you read in the app (left blank on purpose — Tesla prices vary by site and hour). The per-100-mile and per-year gap is the difference times your miles. EPA kWh/100 mi is used per model.
Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.