EV Range Calculator
How far will your electric car really go on this charge? Enter battery size, state of charge and rated efficiency, then adjust speed, temperature and climate control to see a realistic range and how speed changes it.
Last updated:
100% for a new pack; 85–95% is common after several years.
Buffer you keep for safety.
mi/kWh (or km/kWh). Rated range ÷ battery kWh. Typical 3–4.5 mi/kWh.
mph, or km/h with metric units.
°F, or °C with metric units.
How to use the EV Range Calculator
- Enter your battery: usable kWh, health, starting charge and the reserve you want left.
- Enter rated efficiency in mi/kWh or km/kWh (rated range ÷ battery size).
- Set conditions: average speed, outside temperature and how much heat or A/C you use.
- Read the range plus real-world efficiency and the loss from speed, cold and climate.
- Compare speeds in the table and chart to plan charging stops.
How the EV range estimate works
Range = usable energy ÷ energy used per mile. Usable energy = battery kWh × battery health × (start % − reserve %). Energy per mile starts from your rated efficiency (assumed for mild weather and roughly 55 mph mixed driving) and is adjusted:
- Speed: × (0.6 + 0.4 × (speed ÷ 55)²). About 40% of the rated consumption is treated as aerodynamic drag, which grows with speed squared.
- Temperature: about +0.24% per °F below 70°F and +0.2% per °F above 80°F for battery and drivetrain losses.
- Climate control: heating or A/C power in kW divided by speed, so it hurts most in slow city driving.
Example: 75 kWh, 90% → 10%, 3.8 mi/kWh, 65 mph, 50°F, normal heat: 60 kWh usable, about 0.33 kWh/mi, range about 180 miles.
Typical range impact by condition
| Condition | Typical range change | Why |
|---|---|---|
| 55 mph vs 75 mph | −20% to −30% at 75 mph | Drag rises with speed squared |
| 20°F, heater off | About −12% | Cold battery, thicker lubricants, denser air |
| 20°F, heater on | About −41% | Cabin and battery heating draw several kW |
| 95°F, A/C on | About −17% | A/C compressor and battery cooling |
| City driving 25–40 mph | Often above rated | Low drag and regenerative braking |
Cold and hot weather figures are from AAA's 2019 EV range testing compared with 75°F. Individual cars vary, especially those with heat pumps.
Frequently asked questions
How do I calculate my EV's range?
Multiply the usable battery energy you plan to use by your efficiency. A 75 kWh battery going from 90% to 10% uses 75 × 0.8 = 60 kWh; at 3.5 mi/kWh that is about 210 miles. Real efficiency depends on speed, temperature and climate use.
Why does EV range drop on the highway?
Aerodynamic drag grows with the square of speed, so driving at 75 mph takes noticeably more energy per mile than 55 mph. Unlike gas cars, EVs are most efficient at lower speeds and in stop-and-go traffic where regenerative braking recovers energy.
How much range does an EV lose in cold weather?
AAA testing found that at 20°F, range fell about 12% with the climate system off and about 41% with the heater on, compared with 75°F. Cold slows the battery chemistry, and cabin heating draws several kilowatts. Heat pumps, preconditioning while plugged in and seat heaters reduce the loss.
Does using air conditioning reduce EV range?
Yes, but less than heating. AAA measured about a 17% range drop at 95°F with the A/C on and about 4% with it off. Parking in shade and pre-cooling while plugged in help.
What is mi/kWh and how do I find mine?
Miles per kWh is how far the car travels on one kilowatt-hour. Many cars show it on the trip computer. You can also divide the rated range by the usable battery capacity, for example 300 miles ÷ 82 kWh ≈ 3.7 mi/kWh. To convert from kWh/100 mi, divide 100 by that number.
Why keep a reserve when planning a trip?
Range estimates are never exact; headwinds, hills, rain and traffic change consumption, and chargers can be busy or out of service. Arriving with 10–20% gives a buffer, and many cars also hide a small reserve below 0%.
How accurate is this EV range estimate?
It uses a simple physics-based model calibrated to typical published tests, so it is a planning estimate, not a guarantee. Elevation, wind, tire pressure, payload and towing can shift real range by 10% or more.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.