EV calculator
Home vs Public EV Charging Cost
Compare the cost of the same EV charge using the home and public electricity rates you enter.
Use this calculator
What your result means
This compares two entered electricity rates for exactly the same ideal battery energy. It does not claim that either price is typical.
Worked example
The same 36 kWh charge at two entered rates:
- Home at 25p/kWh
- £9.00
- Public at 70p/kWh
- £25.20
The difference is driven only by the entered price.
Formula
How much difference can the charging rate make?
The amount of battery energy is identical in both sides of this comparison. The difference comes from the electricity prices entered.
That makes the comparison useful when deciding whether to charge at home, use a particular public charger, or compare two charging tariffs. A higher price per kWh becomes more significant as the amount of energy purchased increases.
| Rate | Cost for example charge | Difference vs example home rate |
|---|---|---|
| 10p/kWh | £3.60 | £5.40 saving |
| 15p/kWh | £5.40 | £3.60 saving |
| 20p/kWh | £7.20 | £1.80 saving |
| 25p/kWh | £9.00 | £0.00 difference |
| 35p/kWh | £12.60 | £3.60 additional cost |
| 50p/kWh | £18.00 | £9.00 additional cost |
| 65p/kWh | £23.40 | £14.40 additional cost |
| 80p/kWh | £28.80 | £19.80 additional cost |
What if you use public charging regularly?
A single charging session may show only a modest cash difference, but repeated charging can make the rate difference more important.
For example, the result above compares the same amount of energy at two prices. If a driver repeatedly buys electricity at the higher rate, that price difference is repeated each time.
This calculator deliberately stops at the charging-session comparison. For yearly driving costs, use the Annual EV Charging Cost Calculator with the electricity rate that best represents where you expect to charge.
What the comparison does — and does not — tell you
This calculator answers a narrow question: what would the same ideal amount of battery energy cost at two different electricity prices?
It does not assume that home charging is always cheaper or that public charging is always more expensive. Enter the rates you actually want to compare.
It also does not value convenience, journey time, charger availability or charging speed. Those factors can make a more expensive charging option worthwhile in some situations.
What the comparison means
The same battery energy is priced twice. A higher public rate changes the cost of each charge session directly, although public charging can still be useful when it suits a journey or access needs.
Membership, connection, idle and other pricing structures are not modelled; enter a rate that represents the charge you want to compare.
Assumptions and limitations
- Charging losses and network fees are not separately modelled.
Helpful questions
Is public EV charging always more expensive than home charging?
No. The calculator makes no assumption about which rate is cheaper. It compares the two prices you enter.
Why does public charging sometimes cost much more?
Public charging prices can differ from household electricity prices, particularly where rapid charging and network services are involved. Use the actual rates you want to compare rather than assuming a fixed difference.
Does the comparison include charging losses?
No. Both sides use the same ideal battery energy so that the entered electricity rates can be compared consistently.
Does every public charger charge only by kWh?
Not necessarily. Pricing structures can vary. This calculator models the entered pence-per-kWh rates only and does not add membership, connection, idle or other possible fees.
What if I mostly charge at home but occasionally use public chargers?
Use this calculator to understand the difference for individual sessions. For an annual estimate, use a representative blended electricity price in the Annual EV Charging Cost Calculator.
Does a more expensive public charge mean an EV is more expensive overall?
No. A charging-session comparison is only one part of vehicle cost. Ownership comparisons also depend on mileage, efficiency, depreciation and other recurring costs.
Related calculators
- EV Charging Cost Calculator
Estimate the cost of an EV charging session.
- EV Charging Time Calculator
Estimate idealised EV charging time from charger power.
- Annual EV Charging Cost Calculator
Estimate annual EV electricity cost from mileage and efficiency.