EV calculator
EV Charging Membership Break-even Calculator
Estimate how much public charging is needed before a paid membership costs less than PAYG.
Use this calculator
What your result means
The threshold is the monthly public-charging energy at which the lower member price offsets the membership fee. It uses only the entered monthly fee and pence-per-kWh prices.
When the member price equals PAYG, there is no usage-based price advantage. When the member price is higher, membership cannot pay back through the entered energy rate. A zero fee produces the zero-usage threshold defined by the model.
Canonical worked example
Illustrative inputs only: £10/month membership, 79p/kWh PAYG and 65p/kWh member charging. No network or live tariff is implied.
- Energy-price difference
- 14p/kWh
- Break-even charging usage
- 71.43 kWh/month
- Break-even miles at 3.5 miles/kWh
- 250 miles/month
- PAYG cost at 75 kWh
- £59.25
- Member cost at 75 kWh
- £58.75
£10 ÷ £0.14 is approximately 71.43 kWh/month. The example uses the same membership helper as the calculator.
Formula
Monthly public-charging usage sensitivity using illustrative membership inputs
| Monthly public charging | PAYG cost | Member cost | Difference |
|---|---|---|---|
| 25 kWh | £19.75 | £26.25 | Costs £6.50 more |
| 50 kWh | £39.50 | £42.50 | Costs £3.00 more |
| 75 kWh | £59.25 | £58.75 | Save £0.50 |
| 100 kWh | £79.00 | £75.00 | Save £4.00 |
| 150 kWh | £118.50 | £107.50 | Save £11.00 |
How to interpret the threshold
The break-even result is a usage threshold, not a recommendation to buy a membership. Above the threshold, the lower member energy price can outweigh the fee under the entered assumptions; below it, PAYG may cost less.
The supporting comparison applies the entered usage to both prices. It includes the membership fee in the member cost so you can see the actual monthly difference for your expected charging volume.
Charges outside this comparison
This page models a monthly membership fee and pence-per-kWh energy rates only. It does not add connection, idle, parking, minimum-spend, roaming, cancellation or other charges that may apply in a real charging arrangement.
Use the terms and prices relevant to the plan you are considering. The defaults are illustrative and are not live public-charging tariffs.
Practical guidance
Estimate the public charging you genuinely expect to use in a typical month, rather than your total EV charging including home charging. Compare several months if your travel is seasonal or irregular.
Recheck the calculation if the monthly fee or either energy rate changes. A membership can be worthwhile in a high-use month but not in a month with little public charging.
Assumptions and limitations
- Only the entered monthly fee and pence-per-kWh energy prices are included.
- The same public-charging kWh amount is used for PAYG and member comparisons.
- Miles are an optional conversion using the miles/kWh entered; the pricing calculation itself is based on kWh.
- No named network, live tariff, connection fee, idle fee or other plan condition is assumed.
Helpful questions
How is membership break-even calculated?
The monthly membership fee is divided by the per-kWh discount between PAYG and member pricing.
What if the member and PAYG prices are the same?
There is no usage-based price advantage, so the page shows no conventional break-even.
What if the member price is higher than PAYG?
The membership does not pay back through the entered energy rate, even before considering the monthly fee.
What happens if the membership fee is zero?
The model gives a zero-usage threshold when the member energy price is lower, because no fee needs to be recovered.
Can I compare a public rate with home charging?
Yes. Use Home vs Public EV Charging Cost to compare the cost of the same entered charge at two rates.
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