EV calculator
EV Charging Cost Calculator
Estimate the ideal electricity cost of a specific EV charge session.
Use this calculator
What your result means
This charge-session estimate uses ideal battery energy: no charging losses are assumed, so real grid electricity and cost can be higher.
Worked example
A 60 kWh battery charged from 20% to 80% at 25p/kWh:
- Energy added
- 36 kWh
- Cost
- £9.00
Use the entered electricity price; no live tariff is assumed.
Formula
Charge range reference at 60 kWh and 25p/kWh
| Charge range | Energy | Cost |
|---|---|---|
| 20%–80% | 36 kWh | £9.00 |
| 10%–80% | 42 kWh | £10.50 |
| 20%–100% | 48 kWh | £12.00 |
How electricity price changes charging cost
Charging cost changes directly with the electricity price you pay. For the same amount of energy added to the battery, doubling the price per kWh doubles the estimated charging cost.
The table below keeps the example battery and charge range unchanged and varies only the electricity price. These are illustrative rates rather than current tariff averages.
| Electricity price | Energy added | Estimated charging cost |
|---|---|---|
| 10p/kWh | 36 kWh | £3.60 |
| 15p/kWh | 36 kWh | £5.40 |
| 20p/kWh | 36 kWh | £7.20 |
| 25p/kWh | 36 kWh | £9.00 |
| 35p/kWh | 36 kWh | £12.60 |
| 50p/kWh | 36 kWh | £18.00 |
| 65p/kWh | 36 kWh | £23.40 |
| 80p/kWh | 36 kWh | £28.80 |
Why the amount paid at the charger can be higher
The calculator estimates the energy added to the battery. In real charging, some electricity is lost between the grid and the battery, so the amount drawn from the charger can be higher than the increase in usable battery energy.
Your actual cost can also depend on the tariff structure. Some public charging services may use pricing or fees that are not represented by a simple pence-per-kWh calculation.
For that reason, treat the result as a transparent energy-cost estimate based on the values entered rather than a prediction of a particular charging bill.
What changes your charging cost?
Battery capacity, charge range and the electricity price all matter. Charging 20%–80% adds 60% of the battery; a 0%–100% charge adds the full battery capacity.
Assumptions and limitations
- Ideal battery energy is used; charging losses are not modelled.
Helpful questions
How do I calculate the cost of charging an electric car?
Enter the battery capacity, current charge level, target charge level and electricity price. The calculator estimates the battery energy added and multiplies it by the entered price per kWh.
Does this calculator include charging losses?
No. It calculates ideal battery energy added. Real electricity drawn from the grid can be higher because charging is not perfectly efficient.
Is charging from 20% to 80% the same as charging 60% of the battery?
In this model, yes. A 20% to 80% charge adds 60 percentage points of the battery's stated capacity. A 60 kWh battery therefore receives 36 kWh of ideal battery energy.
Why can my actual charging bill be higher?
Charging losses can increase grid electricity use, and the tariff may contain pricing or fees not represented by the entered pence-per-kWh rate.
Can I use this for home and public charging?
Yes. Enter the electricity price you actually want to test. For a direct comparison between two rates, use the Home vs Public EV Charging Cost calculator.
Related calculators
- EV Charging Time Calculator
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- Annual EV Charging Cost Calculator
Estimate annual EV electricity cost from mileage and efficiency.
- Home vs Public EV Charging Cost
Compare the same EV charge at home and public rates.