Continue your plan
Useful next calculations
Rates & sources
DVLA, HMRC fuel advisory rates and manufacturer-published figures. Real-world results vary by driving style.
Source: DVLA / HMRC fuel advisory rates — check the linked guidance and any live quote before acting.
When to use this calculator
- When you need a fast estimate before making a bigger decision.
- When you want to compare a few scenarios using the same assumptions.
- When you need a clearer starting point before using a detailed quote or formal document.
- When you want to sanity-check a figure you have seen elsewhere.
A realistic UK planning example
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
| Input | Value |
|---|---|
| Annual Miles | 10000 |
| Petrol Car MPG | 40 |
| Petrol Price Per Litre (£) | £0.30 |
| EV Miles Per kWh | 4.5 kW |
After entering these figures, review petrol annual cost, ev annual cost and annual saving together rather than in isolation. Then rerun the tool with one input adjusted.
How to read your results
Petrol Annual Cost
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
EV Annual Cost
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
Annual Saving
The recurring yearly benefit of the change or upgrade under the assumptions you entered.
Method & assumptionsAuthoritative sources
This calculator compares the estimated annual running costs of an electric vehicle against a petrol equivalent based on your annual mileage, home electricity rate, petrol price, and the efficiency figures for each vehicle. EV efficiency is expressed in miles per kWh; petrol efficiency in MPG. The comparison covers fuel or energy costs only — it does not include purchase price differences, depreciation, insurance, or servicing, all of which vary significantly by model and driver profile. Public charging costs are not factored into the default calculation; if you rely on public chargers for a portion of your charging, adjust the electricity rate upward accordingly to reflect your blended cost per kWh.
Common mistakes
- !Using optimistic assumptions without testing a more cautious scenario.
- !Comparing outputs from different tools without checking that the inputs match.
- !Treating the result as a final quote instead of a planning estimate.
- !Rounding inputs too aggressively.
What to do next
- Try at least one more scenario so you can compare a realistic range.
- Use the related calculators below to cross-check the decision from another angle.
- Write down the key outputs from your best scenarios before you decide.
- If the result surprises you, change one input at a time to isolate the driver.
Frequently asked
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