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EV Charger Cost Calculator
Calculate EV home charging costs, annual electricity usage, cable sizing for installation, and savings compared to petrol.
Typical UK average 7,400 miles
Standard daytime rate (Ofgem cap ~26.1p Jul–Sep 2026)
Night/off-peak tariff rate
Smart charger scheduling
Equivalent petrol vehicle
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How We Calculate This
This calculator estimates the cost of charging your EV at home based on your annual mileage, vehicle efficiency, and electricity tariff, with cable sizing guidance for installation.
Charging cost calculation
- Annual kWh: Annual miles / vehicle efficiency (mi/kWh)
- Blended rate: Weighted average of peak and off-peak tariffs
- Annual cost: Annual kWh x blended electricity rate
- Petrol comparison: Annual miles / MPG x litres-per-gallon x petrol price
Cable sizing
Cable size is selected per BS 7671 based on charger current rating, cable run length, and installation method. For an EV charger power circuit, voltage drop should be kept within 5% (11.5 V on a 230 V supply) measured from the origin to the charge point, per BS 7671 Appendix 4 and the IET Code of Practice for EV Charging Equipment Installation (5th Edition). Many installers design to a tighter margin to leave headroom for the upstream drop on long supply tails.
Frequently Asked Questions
At the standard daytime rate (around 26.1p/kWh under the Ofgem cap for 1 July to 30 September 2026, varies by region and quarter), a typical EV costs roughly 8p per mile. With a dedicated EV off-peak tariff (around 7.5p/kWh), this drops to 2-3p per mile. A 10,000-mile annual driver who charges mostly off-peak would pay approximately £340-820 per year depending on tariff, compared to £1,600+ for petrol.
A 7kW single-phase charger draws 32A and typically requires 6mm² twin and earth cable for runs up to 20m, or 10mm² for longer runs. The exact size depends on cable run length, installation method, and ambient temperature per BS 7671. A dedicated 32A MCB and 30mA Type A RCD are required.
Most UK homes have single-phase electricity supply, which limits charging to 7kW. A 22kW charger requires a three-phase supply, which is uncommon in domestic properties. For most drivers covering 20-40 miles per day, a 7kW charger provides a full overnight charge in 6-8 hours.
Yes. BS 7671 and the IET Code of Practice for EV charging require a dedicated circuit from the consumer unit. This must include a dedicated MCB, Type A RCD (or Type B for some chargers), and appropriate cable sizing. The installation must be notified to Building Control under Part P.
A typical 7kW home charger installation costs £800-1,500 including the unit, cable run, dedicated circuit, and commissioning. Costs vary based on cable run length, whether the consumer unit needs upgrading, and the charger model. Smart chargers are required for new installations.
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Last updated: June 2026
Verified against UK standards · estimates only, confirm with your supplier.