EV Range Estimator
Estimate an electric vehicle's real-world range from battery capacity and efficiency, accounting for 90% usable charge.
How to use this tool
- Enter the battery pack capacity from the manufacturer spec sheet.
- Enter your expected real-world efficiency in miles per kWh.
- Adjust the usable battery percentage (90% is a common default).
- The calculator returns usable energy and estimated range.
Estimate how far your EV can travel on a full charge under real-world conditions.
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
Usable energy (kWh) = Battery capacity (kWh) × Usable battery (%) ÷ 100
Estimated range (miles) = Usable energy (kWh) × Efficiency (mi/kWh)
How it works
This estimator calculates real-world EV range by first determining the usable portion of the battery pack (manufacturers reserve a buffer to protect cell longevity), then multiplying the usable energy by the vehicle's energy efficiency rating in miles per kWh.
Results are an approximation; actual range depends on driving speed, climate, climate control use, terrain, and battery age, all of which can significantly reduce the figure shown.
Worked example
- Usable energy: 75 kWh × 90% ÷ 100 = 67.5 kWh
- Estimated range: 67.5 kWh × 3.5 mi/kWh = 236.25 miles
A 75 kWh battery with 90% usable capacity at 3.5 mi/kWh yields 67.5 kWh usable and an estimated range of 236.25 miles.
Common mistakes to avoid
- Using the EPA range rating directly -- cold weather, highway speeds, and HVAC use can cut effective range by 20-40%.
- Assuming 100% usable battery capacity; most EVs limit charging to 80-90% for daily use to protect battery longevity.
- Confusing EPA efficiency (MPGe) with kWh per mile -- to get miles per kWh, divide 33.7 by the MPGe rating.
Key terms
- Battery capacity (kWh)
- The total energy storage of the EV battery pack, measured in kilowatt-hours, representing its gross maximum charge.
- Usable battery (%)
- The percentage of total battery capacity the vehicle's management system allows to be used; the remainder is reserved to protect battery health and longevity.
- Usable energy (kWh)
- The actual energy available for driving, equal to total capacity multiplied by the usable percentage.
- Efficiency (mi/kWh)
- How far the vehicle travels on each kilowatt-hour of energy consumed; higher values indicate a more efficient drivetrain and aerodynamics.
- Estimated range (miles)
- The projected distance the EV can travel on a full usable charge under the assumed efficiency conditions.
Frequently asked questions
- What affects EV range?
- Temperature (cold reduces range), speed (highway driving is less efficient), climate control use, and payload all affect real-world range. Efficiency drops ~20–40% in winter.
- Why is usable battery less than total capacity?
- EV manufacturers reserve a buffer at the top and bottom to protect battery health. A 75 kWh pack typically has about 67–72 kWh usable.