Sourced fact
Each amount can be expanded into its input quantity, formula, dated rate, unit and fee treatment.
Maintenance · UK
EV cost calculation method
Every money result expands to named input quantities multiplied by dated rates, with units, VAT treatment and fixed fees shown. Home region and payment method are matched explicitly, while public PAYG, App, RFID, subscription and roaming prices remain separate scenarios. Missing or stale rates remove the result instead of becoming zero, and modelled energy is never presented as a meter measurement.
Ofgem: Energy price cap unit rates and standing charges
Reviewed
Key facts and evidence
For UK EV cost methods reviewed on 13 August 2026, calculations expose quantity, formula, dated rate, unit, VAT, region, payment channel and fixed fees. E2 holds current Ofgem benchmark rows for 1 July to 30 September 2026, but no redistributable supplier EV-tariff examples. The limit is input quality: stale or missing rates yield unknown, not zero or claimed savings.
Ofgem: Energy price cap unit rates and standing charges
Sourced fact
A rate retains its region, payment method, meter or charging context, VAT basis and effective period.
Sourced fact
PAYG, contactless, App, RFID, subscription and roaming prices are separate scenarios rather than one blended price.
Sourced fact
A required missing or stale quantity, rate or fee makes the dependent result unknown and removes savings claims.
How EV Evidence calculates home and public charging costs from dated rates, explicit units, payment channels, fixed fees and labelled assumptions.
Calculation basis
Variable energy cost equals the stated energy quantity multiplied by the matching unit rate. The output identifies whether quantity is meter-measured, operator-reported, observed from a session receipt or modelled from distance and efficiency. Conversion factors and rounding are applied only after the unrounded calculation.
Home charging
The calculator selects the applicable region, payment method, meter type and effective period. Unit rates and standing charges retain their VAT basis. A standing charge is shown separately and is added to a charging decision only when the scenario makes it incremental; an Ofgem benchmark is not described as a household bill cap.
Public charging
Contactless or other PAYG, operator App or RFID, subscription and roaming are calculated independently for the same stated session. Session, connection, parking and idle fees remain separate unless the source explicitly includes them in a displayed pence-per-kWh maximum. An operator price is first-party reported, not an independent measurement.
Subscription break-even
Where both current rates and the monthly fee are known, break-even monthly energy equals the fee divided by the positive per-kWh saving. A zero or negative rate difference has no break-even claim. Missing fees, mismatched coverage or stale prices produce unknown rather than a fabricated threshold.
Current E2 boundary
The E2 Ofgem artefact contains dated benchmark rows, while supplier EV-tariff examples remain an empty state because an explicit redistribution licence was not verified. The method therefore does not populate supplier comparisons from fixtures, memory or an old tariff page.
What to do next
Use a cost result as a dated scenario and check the current provider price before making a purchase or tariff decision.
Immediate action: Review the quantity basis, tariff period, region, payment channel, VAT and every fixed fee.
- Stop relying on the result when a required rate is stale, a payment channel differs, or measured and modelled energy cannot be distinguished.
Professional hand-off
- Ask the energy supplier or chargepoint operator to confirm the current tariff, and use an independent financial adviser for material personal decisions.
Questions this record can answer
What does the sourced evidence say about calculation basis?
Variable energy cost equals the stated energy quantity multiplied by the matching unit rate. The output identifies whether quantity is meter-measured, operator-reported, observed from a session receipt or modelled from distance and efficiency. Conversion factors and rounding are applied only after the unrounded calculation.
What does the sourced evidence say about home charging?
The calculator selects the applicable region, payment method, meter type and effective period. Unit rates and standing charges retain their VAT basis. A standing charge is shown separately and is added to a charging decision only when the scenario makes it incremental; an Ofgem benchmark is not described as a household bill cap.
What does the sourced evidence say about public charging?
Contactless or other PAYG, operator App or RFID, subscription and roaming are calculated independently for the same stated session. Session, connection, parking and idle fees remain separate unless the source explicitly includes them in a displayed pence-per-kWh maximum. An operator price is first-party reported, not an independent measurement.