EV Range & Charging Cost Calculator
Enter efficiency, battery, electricity and gasoline prices to compare running costs and find the break-even prices.
Step-by-step
- Enter valid values to begin.
Efficiency is taken as energy used at the battery per distance, so charging losses are added on top (wall energy = battery energy / charging efficiency). If you enter an EPA or WLTP label figure measured at the wall, set charging efficiency to 100%. Range is usable kWh × efficiency. Prices are in any one currency, shown as $; US gallon = 3.78541 L, 1 mi = 1.609344 km. Cold weather, speed, towing and battery ageing change real efficiency and range; the figures ignore maintenance, insurance and demand charges.
EV Range and Charging Cost: Comparing Miles to Money
Core Engineering Principles
Efficiency is the number that drives everything else. Americans quote miles per kWh, Europeans quote kWh per 100 km, and tech sheets sometimes use Wh per mile. All three are energy per distance, so we convert to one figure first. A car at 3.5 mi/kWh uses 0.286 kWh per mile, which is 17.7 kWh per 100 km, or 286 Wh/mi. Multiply usable battery capacity by efficiency and you get range: 75 kWh at 3.5 mi/kWh is 262 miles. Winter heating, highway speed and towing can each take 10–30% off that.
Cost is where people fool themselves. Charging losses mean the wall supplies more than the battery receives, so a fair cost per mile uses wall energy, battery energy divided by 0.88–0.92. Public fast charging can cost two or three times the home rate, and the savings shrink fast. That is why we calculate a break-even price. Parity is the electricity price at which the EV costs the same per mile as the gasoline car, and the break-even gasoline price is the mirror image. Far under parity, the decision is easy; close to it, other costs decide.
EV $/mi = (kWh/mi / η) × price • Gas $/mi = $/gal / mpg
Parity price = Gas $/mi / (kWh/mi / η) • Parity gas = EV $/mi × mpg
NEC & Standard References
EPA label ranges are produced from standardised dynamometer tests; the related SAE J1634 defines the multi-cycle test procedure for battery electric vehicles. In Europe the WLTP cycle gives the official range, and it tends to read higher than real motorway driving. We use them only for the concept of rated efficiency; none sets a price. Tariffs, time-of-use rates and incentives vary, so read your actual rate schedule.1. Battery energy per mile = 1 / 3.5 = 0.2857 kWh; wall energy = 0.2857 / 0.90 = 0.3175 kWh/mi.
2. EV cost = 0.3175 × 0.16 = $0.0508 per mile.
3. Gasoline cost = 3.50 / 30 = $0.1167 per mile.
4. Annual: EV $610, gasoline $1,400, saving $790.
5. Range = 75 × 3.5 = 262.5 miles; a full fill costs 75 / 0.9 × 0.16 = $13.33.
6. Parity electricity price = 0.1167 / 0.3175 = $0.368 per kWh; parity gasoline price = 0.0508 × 30 = $1.52 per gallon.
- Don’t double count losses. If your efficiency figure came from a wall-to-wheels label, set charging efficiency to 100% or the cost is overstated by about 10%.
- Check the unit toggle. A kWh/100 km value typed under miles per kWh is off by a factor of five or more, so always match the dropdown.
- Use the usable capacity. The brochure figure includes a buffer the car never lets you use.
- Public charging changes the answer. Run the mixed option with your real share before announcing big savings.
- Range is not a promise. Plan trips on a cold-weather, highway figure with a 10–15% reserve.