# Electric vs petrol and diesel: how to compare running costs

> Compare EV running costs with petrol or diesel using your own figures: a worked example per 100 km and per year, and why where you charge matters so much.

Published: 2026-10-20 · Language: en · Source: https://laadpaalvinden.be/en/blog/ev-vs-petrol-diesel-running-costs/

Is driving electric cheaper than petrol or diesel? Sometimes by a wide margin, sometimes barely, and occasionally it costs more. It mostly depends on where you charge. Below you can work it out yourself, step by step.

## Fuel cost per 100 km

For an EV, multiply the consumption in kWh per 100 km by your price per kWh. For a petrol or diesel car, multiply the consumption in litres per 100 km by the price per litre. You'll find your own consumption on the dashboard, or you can work it out with our [guide to calculating consumption](/en/blog/calculate-ev-consumption-kwh-100km/).

Here is an example with assumptions you should replace with your own figures. The prices below are made up for the sums, not current tariffs.

- EV using 18 kWh per 100 km, charged at home at 0.30 euro per kWh: 5.40 euro.
- The same EV at a public AC charger at 0.50 euro per kWh: 9.00 euro.
- The same EV at a fast charger at 0.70 euro per kWh: 12.60 euro.
- Petrol car using 6.5 litres per 100 km at 1.80 euro per litre: 11.70 euro.
- Diesel car using 5.5 litres per 100 km at 1.75 euro per litre: 9.63 euro.

With these assumptions the EV at a fast charger costs more than the petrol car. At home it costs less than half as much.

## From 100 km to a year

Multiply by your yearly distance. At 15,000 km a year, which is 150 times 100 km, that gives:

- home charging: 810 euro,
- public AC charger: 1,350 euro,
- fast charger: 1,890 euro,
- petrol: 1,755 euro,
- diesel: about 1,445 euro.

If you charge 80% of your energy at home and 20% at a fast charger, your EV costs 0.8 times 5.40 plus 0.2 times 12.60, which is 6.84 euro per 100 km. That comes to about 1,026 euro a year. Against the petrol car you save roughly 730 euro.

## Why your charging spot decides the bill

At home you simply pay your own price per kWh. On a public charger the operator adds a margin, and so does your charging card, and fast charging is the most expensive. If you have no driveway and do everything at fast chargers, the advantage shrinks or flips. If you have a fixed place to charge at home or at work, the difference is large. For ways to bring fast-charging costs down, read [how to cut fast-charging costs](/en/blog/cut-fast-charging-costs/).

## Costs beyond fuel

Energy is only part of the bill. Put these side by side for both cars:

- purchase price minus what you can still get for the car later,
- insurance and taxes,
- maintenance: an EV has fewer moving parts and no oil to change, but tyres still wear, sometimes faster than on an ordinary car,
- a wallbox, if you have one installed. Ask a certified installer for a quote and read [how to choose a wallbox](/en/blog/how-to-choose-a-wallbox/).

Say your EV costs 3,000 euro more than the comparable petrol car and you save 730 euro a year on energy. You earn that difference back in a little over four years. Say the wallbox costs 1,500 euro and you mainly use it instead of public AC charging (540 euro a year more expensive in the example): you earn it back in under three years. These amounts are assumptions. Take real prices from quotes and insurance policies.

## Taxes and company cars

Taxes, grants and company car rules change regularly, and they differ by region and by situation. If you drive a company car, the tax treatment often weighs more than the energy cost. Check the current rules with your employer, your accountant or the authorities before you decide.

## When the comparison doesn't hold

- You drive very little. At 5,000 km a year the energy savings are small and the purchase price weighs more.
- You mostly drive long motorway stretches and charge on the way. Then you're close to the fast-charger scenario.
- You compare an EV with a completely different car. Put two cars side by side that really have something in common.
- Your tariff changes. A fixed or dynamic energy contract gives a different price per kWh, and public tariffs move too. Redo the sum when your figures change.

## How to go about it

1. Write down your yearly distance.
2. Find the EV's consumption in kWh per 100 km and the other car's in litres per 100 km.
3. Estimate how much you charge at home, on public chargers and at fast chargers.
4. Look up your current prices per kWh and per litre.
5. Work out the yearly cost, then add the other cost items.

For a single charge you can try the [charging calculator](/en/charging-calculator/), and [how much does charging cost](/en/blog/how-much-does-charging-cost/) explains how the price is built up.