This estimator calculates how much EV driving range may be lost when usable battery capacity declines. It compares original and current usable capacity, then applies the same retention ratio to a chosen full-battery range.
The tool is useful for ownership planning, used-EV comparisons, and interpreting battery health reports. It assumes energy consumption per kilometer is unchanged, so actual range can still move independently with weather, speed, tires, and route.
1. Enter original capacity
Use the vehicle’s original usable battery capacity.
2. Enter current capacity
Use a measured or estimated current usable capacity.
3. Add the original range basis
Choose rated or real-world range and keep that basis consistent.
4. Apply a seasonal adjustment
Use a negative percentage for cold-weather or other expected efficiency penalties.
5. Compare range retention
Separate battery-related loss from the optional operating-condition adjustment.
The main result is the difference between the original range and the adjusted current estimate.
The optional seasonal adjustment changes consumption assumptions; it is not battery degradation.
Given: 75 kWh original capacity, 68 kWh current capacity, 450 km original range, and a -10% seasonal adjustment.
Calculation: Retention = 68 ÷ 75 = 90.67%. Battery-related range = 450 × 0.9067 = 408 km. Adjusted range = 408 × 0.90 = 367.2 km. Loss = 450 − 367.2 = 82.8 km.
Result: Estimated adjusted range loss is 82.8 km.
Yes, by multiplying original usable capacity by the reported health percentage, provided the report uses a compatible definition.
It distinguishes temporary efficiency changes from permanent capacity loss.
The calculator does not allow it. Occasional test results above the nominal figure usually reflect measurement variation or conservative factory ratings.
Proportional scaling is a practical approximation. Vehicle software and efficiency changes can make the relationship differ.
It is useful for comparison, but observed range under consistent conditions is more informative for personal use.