EV Range

Estimating Driving Range From Battery Capacity and Efficiency

An electric vehicle’s driving range is its battery capacity multiplied by how efficiently it turns each kilowatt-hour into miles traveled. Enter your EV’s usable battery capacity, your vehicle’s real-world efficiency in miles per kWh, and how full the battery currently is, and this calculator returns your estimated range at that charge level alongside the full-charge range for comparison.

This is distinct from the EV Charging Cost Calculator calculator, which estimates what charging costs rather than how far you can drive, and the EV Charging Time Calculator calculator, which estimates how long charging takes rather than how far the result gets you.

Key Factors to Consider

• Battery capacity itself shrinks somewhat over the vehicle’s life. Like all lithium-ion batteries, an EV battery loses some usable capacity through age and charge cycles — the U.S. Department of Energy notes EV batteries are generally designed to last 8 to 15 years depending on climate, but usable capacity at year 5-8 is typically somewhat lower than when new. If you know your battery has degraded, enter a reduced capacity rather than the vehicle’s original spec.
• Regenerative braking can make city-driving efficiency competitive with (or better than) highway efficiency — unusual compared to a gas car, where highway driving is typically more efficient. Frequent stop-and-go driving recovers energy back into the battery on each brake, which is part of why real-world efficiency varies so much by driving context.
• Preconditioning the battery and cabin while still plugged in (common in cold weather) can noticeably improve real-world range and charging speed on a cold-weather drive compared to starting from cold, since a cold battery is less efficient and often charges more slowly too.

Useful to Know

For long-term battery health, most manufacturers recommend not routinely charging to 100% or running the battery down near 0% for everyday driving. A common general guideline is to keep regular daily charging in roughly the 20%-80% range, reserving a full 100% charge for longer trips where you need the extra range. Spending extended time at either extreme (very full or very empty) is generally understood to accelerate battery degradation faster than staying in a more moderate range — check your specific vehicle’s manual for its manufacturer’s own guidance, since recommendations can vary somewhat by model.

The Formula

$$\vB{\text{Full Range}} = \vA{\text{Battery Capacity}} \times \text{Vehicle Efficiency (mi/kWh)}$$ $$\vD{\text{Estimated Range}} = \vB{\text{Full Range}} \times (\vC{\text{Current Charge \%}} \div 100)$$

Worked Example

A 75 kWh battery on a vehicle that travels 3.5 miles per kWh, currently at 60% charge:

1. Full Range: $\vA{75} \times 3.5 = \vB{262.5} \text{ miles}$.
2. Estimated Range: $\vB{262.5} \times (\vC{60} \div 100) = \vD{157.5} \text{ miles}$.

At a full 100% charge, the same vehicle would have its full 262.5 miles of range available.