Before you begin
What decides whether an EV pays back
Every price is yours to enter, so the answer moves with your fuel, your electricity and the quotes you hold. Insurance, servicing, tyres, finance and resale value are left out because none can be known in advance. Revenue's VRT relief on a new EV applies to cars registered before 31 December 2026 and says nothing about 2027, so if your quote already has relief or a grant taken off, the result also shows the payback without it.
Use the on-the-road price quoted to you for each car, so delivery and registration are in both.
Enter real-world consumption for both cars. A cold winter or a lot of motorway driving raises an EV's figure more than a petrol car's.
Charge share is the part of your energy bought at home, not the number of sessions.
Reading the answer
Reading the payback and the break-even price
Payback is the price gap divided by the yearly saving, and it only means something against how long you will keep the car. Resale value is not modelled.
The break-even pump price is the fuel price at which the two cars cost the same to run. If it is well below what you pay now, the EV's running-cost advantage does not depend on fuel staying dear.
The result also gives the average charging rate, and the share of charging done at home, at which the two cars cost the same to run. They matter most if you cannot be sure of charging at home.
A negative saving means the petrol or diesel car costs less to run on these figures.
Boundaries
Assumptions and limitations
Working assumptions
- Both cars cover the same distance every year, and the prices you enter hold for the whole year.
- Home and public charging are blended by the share you enter into one average rate.
Where to be careful
- Insurance, servicing, tyres, finance, tolls, depreciation and resale value are not included, and can move the answer either way.
- It does not know whether a grant or relief will still exist when your car is registered. It only shows the payback with and without the amount you enter.
- Company-car tax works differently from this comparison and has its own calculator.
Worked example
The same question, answered end to end
A driver covering 15,000 km a year in a 7 L/100 km petrol car, weighing an EV that uses 18 kWh/100 km and is charged 80% at home.
What was entered
- 15,000 km a year; petrol at €2.00 a litre in a car using 7 L/100 km.
- EV using 18 kWh/100 km, charged 80% at home on 44c and 20% in public on 60c.
- EV on the road at €38,000, with €5,000 of relief and grant already in that price, against €30,000 for the petrol car.
- Motor tax of €120 for the EV and €280 for the petrol car.
How it is worked out
Petrol: 15,000 km at 7 L/100 km is 1,050 litres, or €2,100 a year, plus €280 motor tax.
EV: 15,000 km at 18 kWh/100 km is 2,700 kWh. The blended rate is 80% of 44c plus 20% of 60c, or 47.2c, so €1,274, plus €120 motor tax.
The yearly saving is the difference between the two running costs.
The price gap is €38,000 less €30,000, or €8,000, so payback is the gap divided by the saving.
Without the €5,000 the gap is €13,000, and the payback is longer.
The break-even pump price is the EV's running cost less the petrol car's motor tax, divided by the 1,050 litres.
What the tool returns
- Yearly saving with the EV
- €986
- Payback on the price gap
- 8.1 years
- Pump price where the two cost the same
- €1.06/L
Common questions
Questions about this tool
Which price should I enter for each car?
The on-the-road price you have been quoted, after any discount, grant or VRT relief the dealer has already taken off. Put the part of that discount that comes from a grant or VRT relief into the support field as well.
Does it include a home charger?
No. A charger is a separate cost, and an ordinary plug may be enough for low mileage. The EV home-charger grant checker covers the grant, the cost and whether a lead would do.
What does the break-even pump price tell me?
It is the fuel price at which the two cars cost the same to run on your figures. If it is below what you pay now, the EV is cheaper to run; if it is above, the petrol or diesel car is.