EV Range Calculator
How far an electric car actually goes once you take off the unusable part of the battery, the reserve you keep and the cold or the motorway.
Results
The dashed line marks the value you entered.
What this tool does
The range on the window sticker is measured in conditions nobody drives in. This page works from the numbers you can check: the battery's net capacity, the consumption your own trip computer reports, how much worse it gets in the cold or at speed, and how much charge you would rather not go below. The result is the distance you can plan a journey around, alongside the laboratory figure so you can see exactly how much the conditions cost you.
Formula
range = usable energy ÷ real consumption × 100 · consumption is adjusted for the conditions
Variables
| Symbol | Meaning | Unit |
|---|---|---|
b | Battery capacity | kWh |
us | Share of it you can actually use | % |
c | Consumption per 100 km | kWh/100km |
pn | Extra used in cold or at speed | % |
rs | Reserve you want to keep | % |
R | Range | km |
U | Energy you can use | kWh |
C | Consumption in these conditions | kWh/100km |
E | Kilometres per kWh | km/kWh |
I | Range | km |
L | Range lost to the conditions | km |
Worked example
- Battery capacity60 kWh
- Share of it you can actually use95 %
- Consumption per 100 km17 kWh/100km
- Extra used in cold or at speed25 %
- Reserve you want to keep10 %
- Range241 km
- Energy you can use51.3 kWh
- Consumption in these conditions21.3 kWh/100km
- Kilometres per kWh4.71 km/kWh
- Range335 km
- Range lost to the conditions94 km
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
Frequently asked questions
Why is the usable share less than the whole battery?
Because cars keep a slice at the top and the bottom that the driver never touches. Charging a cell right to full or emptying it right down shortens its life, so the management system reserves some and reports zero before the cell is actually empty. The size of that buffer varies between makes, and the manufacturer usually publishes both a gross and a net capacity — the net one is what belongs in this box.
What should I put for the extra used in cold or at speed?
Your own observation, if you have it: the trip computer's average over a cold week against a mild one is the best source there is. Air resistance rises with the square of speed, so motorway cruising costs far more than town driving, and in the cold the battery is both less willing to give up its energy and busy heating the cabin. This box is where all of that goes, as one honest number you chose rather than several I invented.