Calculators · EV and electrical

EV range, energy consumption and battery health calculator

An electric car’s range is simply its usable battery energy divided by how much energy it uses per kilometre. Consumption is quoted in several ways — kWh per 100 km in Europe, Wh per mile or miles per kWh elsewhere, and MPGe on US window stickers. These calculators estimate range, convert between every consumption unit, and work out how much capacity a battery has lost with age.

Driving range from battery and consumption

Divides usable battery capacity by consumption. Use usable rather than gross capacity, and remember that motorway speeds, cold weather and heating can raise consumption by 20–40%.

Results
Range—Distance on the usable capacity minus the reserve.

Formula
range = usable kWh × (1 − reserve) / consumption × 100

Energy consumption unit converter

Converts any EV efficiency figure into all common units, including the US MPGe rating, which treats 33.7 kWh as equivalent to one US gallon of petrol. Lower kWh/100 km is better; higher miles/kWh is better.

Results
kWh per 100 km—kWh/100 kmEnergy used over 100 km.
Wh per km—Wh/kmEnergy used per kilometre.
Wh per mile—Wh/mileEnergy used per mile.
Miles per kWh—mi/kWhDistance per unit of energy.
MPGe—MPGeUS miles-per-gallon-equivalent rating.

Formula
Wh/km = kWh/100 km × 10
mi/kWh = 100 / (kWh/100 km × 1.609)
MPGe = 33.705 / (kWh per mile)

Battery health and capacity loss

Compares a battery’s current usable capacity — or the range it achieves under the same conditions — with its original value, to show state of health. Most EV batteries keep 85–90% of their capacity after 150,000–200,000 km.

Results
State of health—%Current value as a percentage of the original.
Capacity lost—%How much has been lost since new.

Formula
health = current / original × 100

Worked example: a 75 kWh electric car

  1. At 17 kWh/100 km, 75 kWh gives 75 / 17 × 100 = 441 km.
  2. Keeping a 10% reserve leaves 397 km of usable range.
  3. 17 kWh/100 km equals 170 Wh/km, 274 Wh/mile, 3.66 miles/kWh or about 123 MPGe.
  4. If the battery now holds 68 kWh, its state of health is 90.7%.

Typical EV energy consumption

Vehicle typekWh/100 kmmiles/kWh
Small electric carabout 13 – 15about 4.1 – 4.8
Mid-size electric saloonabout 15 – 18about 3.5 – 4.1
Electric SUVabout 18 – 24about 2.6 – 3.5
Electric pickupabout 24 – 32about 1.9 – 2.6
Motorway in winter (any car)add about 20 – 40%

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About these results

Results are theoretical estimates from standard engineering formulas. Real-world figures depend on conditions these formulas do not capture. Always follow the manufacturer's specifications for maintenance, loading and safety decisions.

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