EV calculator

EV Charging Loss Calculator

Estimate grid electricity and energy loss when charging an EV.

Use this calculator

Enter battery energy and a charging efficiency.

What your result means

Charging loss is the difference between energy delivered to the battery and electricity drawn from the grid. It depends on the efficiency entered; no universal loss percentage is assumed.

Worked example

60 kWh delivered at 90% efficiency and 25p/kWh:

Grid energy: 66.67 kWh
Loss: 6.67 kWh
Loss cost: £1.67

Billed grid energy can exceed battery energy added.

Formula

\text{grid kWh}=\frac{\text{battery kWh}}{\text{efficiency}/100};\ \text{loss}=\text{grid kWh}-\text{battery kWh}

Illustrative loss sensitivity for 60 kWh battery energy

Efficiency	Grid energy	Loss
85%	70.59 kWh	10.59 kWh
88%	68.18 kWh	8.18 kWh
90%	66.67 kWh	6.67 kWh
92%	65.22 kWh	5.22 kWh
95%	63.16 kWh	3.16 kWh

Using the result

Use a value that reflects the charging situation you want to model; hardware, temperature and auxiliaries can change losses.