Estimate the cost of installing a home chargepoint, compare electricity tariffs and understand the cost per mile, charging time and possible savings.
Start with your actual driving and electricity prices if you know them. The defaults are editable examples, not a vehicle-specific prediction.
For the chosen public-charging comparison and yearly miles. Constant electricity prices and charging habits assumed; no financing or repairs.
Cumulative charging savings Net installation cost
Your results explain the benefit of the chosen home/public charging comparison.
Use a competent EV chargepoint installer to assess your electrical supply, earthing, RCD protection, charger suitability, cabling, load management and Distribution Network Operator notification or approval. Do not rely on extension leads or assume an ordinary household socket is suitable for routine charging. Check grant rules before committing to installation.
Electricity tariffs, charging times and the share of miles charged away from home can change costs considerably. A cheap overnight tariff can be valuable, but other household electricity rates and tariff conditions may change.
The calculator does not compare vehicle ownership or petrol/diesel costs, public parking charges, subscription fees, EV depreciation, battery wear or full environmental impacts. Public DC fast charging can have different energy losses from home AC charging; this simplified model applies one charging-efficiency assumption to both. Simple charger payback applies only to the explicitly selected public-charging alternative.
Annual battery energy used for driving = annual electric miles ÷ user-entered vehicle efficiency (miles/kWh). Annual purchased charging energy = battery energy ÷ charging efficiency. Electricity is not assumed to be free or lossless.
Home-charged miles = annual electric miles × chosen home-charging fraction. Remaining miles use the public comparison rate. Home blended unit rate = proportion charged in cheap period × cheap rate + remaining home proportion × regular rate. Home electricity cost = home miles ÷ vehicle efficiency ÷ charging efficiency × blended rate. Public electricity cost = public miles ÷ vehicle efficiency ÷ charging efficiency × public rate. All rates are p/kWh converted into pounds.
Annual saving versus the chosen public charging alternative = electricity required for the miles selected for home charging × (public rate − blended home rate). This assumes those miles would otherwise be charged at the selected public price, not using an existing cheap home socket. Net installation cost = installed quote − confirmed award. Simple installation payback = net cost ÷ positive annual comparison savings. No positive saving means no positive payback.
Estimated charging time (hours) = energy to add to the EV battery ÷ [min(home charger output, EV onboard AC limit) × assumed charging efficiency]. Actual charging rates may reduce when the battery warms or nears full charge, and supply limits vary; this is only a rough constant-power illustration. EVs are not always charged from empty to full.
Energy Saving Trust indicative installed smart charger £800–£1,200 (https://energysavingtrust.org.uk/advice/smart-charging-electric-vehicles/). Ofgem standard variable electricity direct-debit Great Britain average 26.32p/kWh for 1 Oct–31 Dec 2026; standing charges are excluded as they generally apply irrespective of EV charging, but additional tariff subscription/standing charges could matter. The default 10p cheap rate and 55p public rate are illustrative and NOT current market guarantees. GOV.UK EV chargepoint grants cover 75% of eligible installation costs, capped at £500 for eligible flat owners, renters and certain on-street arrangements as at November 2026, with strict eligibility, permissions and OZEV-authorised installer conditions; this calculator assumes no award without user confirmation.
Check installer competence and requirements under BS 7671 and all applicable local rules, DNO requirements, permitted charging locations and cross-pavement restrictions. Some chargepoint installations may need planning, landlord/freeholder permissions or meter/service upgrades.