EV Charging Cost Calculator

Estimate charging cost, session time, annual spend, and savings vs petrol — with smart off-peak scheduling and charger comparison.

Your vehicle & session

Quick fill:

Battery size (kWh)

Current charge level (%)

Target charge level (%)

Electricity rate (p/kWh)

Charger power (kW)

Charging efficiency (%)

Off-peak scheduling

Compare peak vs off-peak rates to find the cheapest time to charge. Ideal for Economy 7, Octopus Go, or any time-of-use tariff.

Energy needed (kWh)

Peak rate (p/kWh)

Off-peak rate (p/kWh)

Charger power (kW)

Charger speed comparison

See how different charger types affect cost and time for the same charge session.

Energy to add (kWh)

Home rate (p/kWh)

Public rate (p/kWh)

Annual charging cost

Estimate your yearly home and public charging bill, and see how much you save versus a comparable petrol car.

Annual mileage

Vehicle efficiency (mi/kWh)

Home rate (p/kWh)

% charged at home

Public rate (p/kWh)

Petrol price (p/litre)

Tips for cheaper charging

1

Use an Economy 7 or Octopus Go tariff — off-peak rates as low as 7–9p/kWh can cut your charging bill by 60–70% compared to daytime rates.

2

Avoid charging above 80% regularly — lithium batteries degrade faster when kept at high state of charge for extended periods.

3

Rapid public chargers (50–150kW) are convenient but typically cost 50–80p/kWh. Use them sparingly if cost is a priority.

4

A home 7kW wallbox charges most EVs overnight and is roughly 3× faster than a standard 3-pin socket at the same energy cost.

What this calculator covers

Energy added (kWh usable and drawn from wall, accounting for charger efficiency losses)
Session charging cost and approximate time
Estimated range added and cost per mile
Peak vs off-peak cost comparison and annual savings
Side-by-side charger type comparison (3-pin to ultra-rapid DC)
Annual home and public charging cost with petrol savings estimate

Results are estimates only. Actual costs may vary due to charging losses, high-charge tapering, network session fees, and real-world efficiency differences.