EV Charging Cost & Time Calculator
EV Charging Cost & Time Calculator
Octopus Intelligent and similar tariffs schedule your charging into cheap overnight rate windows automatically — often a significant saving over a standard variable rate for anyone charging at home regularly. Toggle "Off-peak EV tariff" above to see the estimated difference for your vehicle.
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Using the tariff, vehicle, and comparison car settings above, here's roughly what a year of driving costs at different annual mileages:
| Annual mileage | Est. EV cost/year | Est. petrol cost/year | Approx. saving |
|---|
Fuel and electricity prices fluctuate regularly — these figures are for general comparison only and will drift from current prices over time. Update the tariff field above with your actual rate for the most accurate result.
Does a home charger pay for itself?
If you're currently relying on public charging or driving a petrol/diesel car, a home charger can pay for its own installation cost surprisingly quickly — often within a year for higher-mileage drivers. Enter your numbers below to see an estimate.
Frequently Asked Questions
How quickly does a home EV charger pay for itself?
This depends heavily on your annual mileage and what you're currently paying to charge. Someone switching from regular public rapid charging to home charging on a standard tariff, doing average-to-high annual mileage, can often see the installation cost paid back within 12-18 months purely through the difference in per-mile charging cost — and faster still on an off-peak EV tariff.
Is it worth installing a home charger for low annual mileage?
Payback takes proportionally longer at lower mileage, since the per-mile saving accumulates more slowly. That said, convenience (never needing to visit a public charger) is a genuine benefit independent of the financial payback calculation, and is worth weighing alongside the numbers.
Why does the comparison change so much between public DC and petrol?
Public DC rapid charging is priced per kWh at rates well above home electricity tariffs, since it includes the cost of the rapid charging infrastructure itself — so the saving from switching to home charging is usually larger against public DC than against petrol, even though both comparisons typically favour home charging.
Why is DC charging shown as an estimate rather than an exact time?
Unlike AC charging, which holds a fairly steady rate, DC rapid charging follows a charging curve — it's fastest at low charge levels and tapers significantly as the battery fills, especially above around 80%. This calculator applies a typical averaging factor to give a realistic estimate, but real-world DC charging time can vary noticeably from vehicle to vehicle and even session to session depending on battery temperature.
How much could an off-peak EV tariff actually save me?
This depends heavily on your current standard rate, how much of your charging happens at home overnight, and your annual mileage — but for regular home charging, off-peak EV tariffs are typically a significant saving over a standard variable rate, since the off-peak rate is usually a fraction of the standard one. Use the toggle above to see the estimated difference for your specific vehicle and mileage.
Why does the calculator ask for charging losses?
Not all the electricity drawn from the wall ends up stored in the battery — some is lost as heat during AC-to-DC conversion inside the vehicle. This is normal and applies to every EV, typically in the 8-12% range for AC (home) charging, which is why the energy you're billed for is always slightly more than the energy your battery gains.
Why is my actual charging time longer than the calculator estimates?
This calculator assumes a fairly steady charging rate. In reality, charging speed can be affected by battery temperature, dynamic load balancing, or vehicle-specific charging curves — see our guide on why EV charging speed varies for the full picture.
This calculator provides estimates for general guidance only, based on typical figures and the information entered. Actual results vary by vehicle, conditions, and real-world charging behaviour. EcoHarmony may receive a benefit if you sign up to Octopus Energy via the link above.