Car & Vehicle

EV Range Calculator

How far an electric vehicle goes on a charge, from your own efficiency and the charge you are willing to use.

7 inputs Free, no sign-up

Your figures

From the handbook or the manufacturer's specification. Usable capacity is a little below the gross figure, because a buffer is held back at each end to protect the cells - and it differs by variant, so it is not filled in here.

What your car's own trip computer reports, usually as km/kWh or Wh/km. It swings a long way with speed, temperature and the climate control, so use the figure from conditions like the ones you are planning for.

From your own bill for home charging, or the price shown on the charger for a public one. Public rates are commonly several times the domestic tariff.

Try an example

Result

Your result

Enter your figures and the result appears here.

Estimates only. Rates, fees and specifications change. Confirm against the official source before you rely on a figure — see our disclaimer.

About this calculator

Range is the usable energy multiplied by the efficiency, and only one of those is a property of the car. Efficiency swings by 30% or more with speed, temperature, terrain and the climate control, which is why a single rated range is such a poor guide to a particular journey.

Enter the efficiency your car is actually reporting and the charge you are willing to arrive on. The result is a range you can plan against rather than a number from a brochure.

How to use this calculator

  1. Enter the usable battery capacity from the handbook.
  2. Enter the efficiency from the car's trip computer, in km/kWh or Wh/km — whichever it shows.
  3. Set the starting charge and the charge you want left when you arrive. Ten per cent is a common margin; arriving at zero is not a plan.
  4. Add your electricity rate for the cost per kilometre.

The formula

Usable energy = Capacity x (Start - Arrive) / 100
Range         = Usable energy x Efficiency in km/kWh

An efficiency in Wh/km is converted first: km/kWh is 1,000 divided by it. That is a reciprocal, so 160 Wh/km is 6.25 km/kWh and the direction of "better" flips between the two units.

SymbolMeaningUnit
Capacity Usable battery capacity kWh
Efficiency What the car achieves km/kWh or Wh/km
Arrive on Charge left at the end %

Worked example

A 30 kWh battery at 6 km/kWh, from 100% down to 10%:

Usable = 30 x 0.90 = 27 kWh
Range  = 27 x 6    = 162 km

Run flat it would be 180 km, which is a fact rather than a plan.

Notes and limits

  • A cold highway run can use half again what a mild city run does. Plan a long trip on the efficiency you see in those conditions, not on your best figure.
  • Heating in winter draws from the same battery as the motor, and unlike a petrol car there is no waste heat to use. Climate control is a real share of winter range.
  • Regeneration makes city driving relatively efficient for an EV — the opposite of a petrol car, where the city is the worst case.
  • Usable capacity is below the gross figure, and a battery loses capacity slowly over the years. An older car's real usable figure is lower than the one in the brochure.
  • The EV efficiency converter moves a figure between km/kWh, Wh/km, kWh/100 km and mi/kWh.

What this calculation assumes

  • Efficiency holds for the whole journey, which speed and temperature both break.
  • Battery capacity and efficiency are figures you entered. No claimed range is used.
  • Cost per kilometre ignores charging losses - the EV charging cost calculator includes them.

Frequently asked questions

How far can my electric car go on a charge?

Multiply the usable energy by your efficiency. A 30 kWh battery used from 100% to 10% gives 27 kWh; at 6 km/kWh that is 162 km. Your efficiency is the figure that decides it, and it is on the car's own display.

Why is my range lower than the claimed figure?

Claimed ranges come from a standardised test cycle at moderate speeds with the climate control off. Real driving - especially fast highway driving in cold or very hot weather - uses considerably more energy per kilometre.

What charge should I plan to arrive on?

Enough to reach a charger you know about. Ten per cent is a common margin on a familiar route and too little on an unfamiliar one. The page leaves it to you rather than picking a number.

Does using the heater really reduce range?

Measurably, yes. An electric car has no engine waste heat, so cabin heating comes from the traction battery. In cold conditions it can account for a significant share of the energy used.

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