How much does it cost to charge an EV at home?

At the standard UK electricity rate of 24.5p/kWh, a typical EV costs about 7-8p per mile. With an off-peak tariff (7.5p/kWh), this drops to 2-3p per mile. A 10,000-mile annual driver would pay approximately £240-780 per year depending on tariff, compared to £1,500+ for petrol.

What size cable do I need for a 7kW EV charger?

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.

Should I get a 7kW or 22kW charger?

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.

Do I need a dedicated circuit for an EV charger?

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.

How much does EV charger installation cost?

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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EV Charger Cost Calculator

Calculate EV home charging costs, annual electricity usage, cable sizing for installation, and savings compared to petrol.

Charger Power

7kW is standard for single phase

Annual Mileage

Typical UK average 7,400 miles

Vehicle Efficiency

Electricity Price

Standard daytime rate

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. Voltage drop must be kept within 5% for the circuit.