EV Charging Cost Calculator
Work out the kWh required and cost to charge your EV between any two charge levels.
How it works
Energy added to the battery is the capacity multiplied by the percentage-point gap between your starting and target charge. Because charging isn’t perfectly efficient, more energy than that is actually drawn from the wall — dividing by the efficiency percentage gives that grid figure, which is what your electricity rate is applied to.
Curious how that compares to running a petrol car over the same distance? Try the EV vs Petrol Running Cost Calculator.
Cost = (Battery Capacity × Charge Added % ÷ Efficiency) × Electricity Rate
Worked example
A 60kWh battery, charging from 20% to 80%, 90% efficiency, at $0.30/kWh:
- Energy added to battery
- 60 × 60% = 36 kWh
- Energy drawn from the grid
- 36 ÷ 0.9 = 40 kWh
- Cost
- 40 × $0.30 = $12.00
Frequently asked questions
Charging isn't perfectly efficient — some energy is lost as heat converting AC power from the wall to DC power stored in the battery, plus the battery management system's own overhead. That loss is typically 5-15%, which is what the charging efficiency setting accounts for.