Sourced fact
A metered charging reading can be used directly as the unit-rate input.
Regulation · GB
Which kWh input to use for home charging
Use electricity measured at the home supply or chargepoint when that reading is available. A battery-added kWh figure is a different input and needs an explicit charging-loss conversion. Keep the unit as kWh and pair it with a dated price in pounds or pence per kWh.
Ofgem: Price cap unit rates and standing charges
Reviewed
Key facts and evidence
Within the UK, this Great Britain guide is current as of 13 August 2026. Its conclusion is to use metered charging kWh where available and to label battery-added energy separately. The applicable E2 rates run from 2026-07-01 to 2026-09-30; this page does not infer energy use from battery capacity or distance.
Ofgem: Price cap unit rates and standing charges
Sourced fact
Battery-added kWh must be labelled separately before any loss conversion.
Sourced fact
The E2 Ofgem unit-rate field is pounds per kWh inclusive of VAT.
Choose a transparent electricity input for a Great Britain home EV charging calculation without mixing battery and meter energy.
Preferred cost input
Input: metered home-charging kWh for the chosen period. Formula: metered kWh × dated unit rate. Dated rate: the selected Ofgem region and payment-method row, effective 2026-07-01 to 2026-09-30 and inclusive of VAT. The expanded amount must retain the reading period and source.
Battery-added energy
Battery-added kWh is not silently treated as metered electricity. When it is the only input, the separate user-entered charging-loss field converts it to estimated supply kWh before the dated rate is applied; battery capacity, distance and state-of-charge changes are not substituted automatically.
What to do next
Use an existing bill, app or chargepoint energy record only when its scope and unit are clear.
Immediate action: Label the input as metered charging kWh or battery-added kWh before calculation.
- Stop if the reading period, unit or measurement location is unknown.
Professional hand-off
- Ask the supplier or chargepoint provider what the displayed kWh measures if the record is ambiguous.
Questions this record can answer
What does the sourced evidence say about preferred cost input?
Input: metered home-charging kWh for the chosen period. Formula: metered kWh × dated unit rate. Dated rate: the selected Ofgem region and payment-method row, effective 2026-07-01 to 2026-09-30 and inclusive of VAT. The expanded amount must retain the reading period and source.
What does the sourced evidence say about battery-added energy?
Battery-added kWh is not silently treated as metered electricity. When it is the only input, the separate user-entered charging-loss field converts it to estimated supply kWh before the dated rate is applied; battery capacity, distance and state-of-charge changes are not substituted automatically.