How to Calculate EV Remaining Range
Your EV's real-world range equals battery level (kWh) × adjusted efficiency (mi/kWh). The EPA-rated efficiency assumes ideal conditions, so real driving requires corrections for climate control and road type.
Using AC at moderate intensity reduces efficiency by about 18%. Highway driving at high speeds adds roughly another 10% reduction due to aerodynamic drag. Cold weather with the heater running can cut range by 30–40% in severe conditions.
Formula
Adjusted Efficiency = Rated Efficiency × (1 − AC Loss) × (1 − Drive Loss)
Range = Battery Level × Adjusted Efficiency
Frequently Asked Questions
Check your vehicle's instrument cluster or the manufacturer app (Tesla, MyChevrolet, FordPass, etc.). Some cars show percentage only — multiply by total battery capacity to get kWh.
The dash estimate is based on recent driving history and learned patterns, while this calculator uses a fixed efficiency formula. Expect a 5–15% difference.
Pre-condition the cabin while still plugged in, use seat heaters instead of cabin heat, and keep speeds moderate. Battery preconditioning before fast charging also helps.