EV Charging Cost & Range Summary
As electric vehicle (EV) adoption expands rapidly across the UK, the cost of charging an electric car varies dramatically depending on where and when you charge.
Charging an EV at home overnight using a dedicated Smart Off-Peak EV Tariff (such as Octopus Intelligent or OVO Charge) can cost as little as 7p per kWh (approx. 1.8p per mile), whereas charging at a motorway public ultra-rapid charger (150kW+) can cost up to 79p per kWh (approx. 20p per mile).
⚙️ Rules & Thresholds
- Key EV Formulas:
Energy Added (kWh) = Usable Battery Capacity × ((Target % - Start %) / 100).Session Charging Cost (£) = Energy Added × (Tariff Rate in Pence / 100).Driving Range Added (Miles) = Energy Added × Efficiency (Miles per kWh).Pence Per Mile Cost (p/mi) = Tariff Rate in Pence / Efficiency (Miles per kWh).
- UK Charging Tariff Benchmarks (2026/27):
- Overnight Smart EV Tariff (Home): ~7.00p / kWh (1.8p – 2.0p per mile).
- Standard Domestic Price Cap (Home): ~24.50p / kWh (6.4p – 7.0p per mile).
- Public Fast Charger (7kW – 22kW): ~45.00p / kWh (11.8p – 12.8p per mile).
- Public Ultra-Rapid Hub (150kW+): ~79.00p / kWh (20.7p – 22.5p per mile).
- Public Charging VAT: Domestic home electricity incurs 5% VAT, whereas public EV charging stations are subject to standard 20% VAT.
📊 Practical Examples
- Battery Usable Capacity: 64 kWh
- Charging Window: 10% to 80% (70% net charge added = 44.8 kWh)
- Tariff Rate: 7.00p per kWh (Overnight Smart EV Tariff)
- Efficiency: 3.8 Miles per kWh
Energy Added: 44.8 kWh
Session Charging Cost: 44.8 kWh × £0.07 = **£3.14**
Driving Range Added: 44.8 × 3.8 = **170.2 Miles**
Running Cost Per Mile: 7.00p / 3.8 = **1.84p per mile**.
📑 Common Pitfalls
- Relying Exclusively on Highway Ultra-Rapid Chargers: Charging solely at 79p/kWh public rapid chargers makes an EV as expensive to run as a petrol car (~20p/mile).
- Overestimating Cold Weather Battery Range: Cold winter temperatures reduce EV efficiency by 15% to 25% (dropping efficiency from 4.0 mi/kWh in summer to 3.0 mi/kWh in winter).
- Confusing Gross Battery Capacity with Usable Capacity: A car advertised with a 60 kWh gross battery may have a usable net capacity of 54 kWh due to protective buffer reserves.
❓ Frequently Asked Questions (FAQ)
Using a dedicated overnight smart EV tariff (at ~7p/kWh), charging a standard 60 kWh electric car battery from empty to full costs just £4.20, providing around 200 to 220 miles of driving range.
A smart EV tariff is a specialized dual-rate domestic electricity tariff offered by UK energy suppliers. It provides a discounted low unit rate (typically 7p/kWh) for 4 to 6 hours overnight when grid demand is low, specifically designed for charging electric vehicles.
Public EV charging costs more because commercial chargepoint operators must cover high hardware installation costs, grid connection upgrades, site lease rents, ongoing maintenance, and standard 20% VAT (compared to 5% VAT on domestic home electricity).
Miles Per kWh (mi/kWh) is the electric vehicle equivalent of Miles Per Gallon (MPG). It measures how many miles an electric car can travel on 1 Kilowatt-hour of battery energy. Efficient EVs achieve 4.0 to 4.5 mi/kWh, while large heavy electric SUVs achieve 2.5 to 3.0 mi/kWh.