How to use this calculator
- Enter or choose usable battery capacity.
- Enter or choose current charge.
- Enter or choose reserve to keep.
- Enter or choose energy use.
- Enter or choose energy use unit.
- The estimated range updates as you type. Use Copy result or Share to keep it.
Method
Energy = Capacity × (Charge% − Reserve%); Range (km) = Energy ÷ (kWh per km × (1 + Adjustment%)); miles = km ÷ 1.609344
- Capacity
- usable battery capacity
- kWh per km
- consumption converted from the chosen unit (1 mile = 1.609344 km)
Worked example
- Energy above the reserve = 75 × (90% − 10%) = 60 kWh.
- Range = 60 ÷ 0.16 kWh/km = 375 km.
- In miles: 375 ÷ 1.609344 = 233.01 mi.
A 75 kWh car at 90%, keeping a 10% reserve and using 16 kWh/100 km, has about 375 km (233 miles) of range.
What the result means
Range scales directly with consumption, so a 20% rise in consumption cuts range by about a sixth. Plan long trips around your worst-case consumption, not the average.
Assumptions and limits
- Consumption stays at the entered average for the whole distance.
- Terrain, wind, speed, temperature and cabin heating can change consumption a lot; the adjustment is your estimate, not a model.
Questions
Why is my range lower than the official figure?
Official test cycles are gentler than many real journeys. Motorway speeds and cold weather raise consumption.
How do I convert mi/kWh to kWh/100 km?
kWh/100 km = 100 ÷ (mi/kWh × 1.609344). For 4 mi/kWh that is about 15.5 kWh/100 km.