Fuel Cost Calculator Ireland
Work out what any journey costs in petrol or diesel — in kilometres, L/100km and euro per litre.
Fuel Type
Measure consumption in
— lower L/100km means better economy.
Irish average as of — edit to match your local price.
Journey Cost
€0.00
Cost per km
0.0c
Litres Needed
0.0
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Fuel Costs in Ireland, Explained
Ireland went fully metric on the roads in 2005, so distances are in kilometres and speed limits in km/h, while cars are rated in litres per 100km. That makes the sum straightforward: kilometres multiplied by consumption, divided by 100, multiplied by the price per litre.
Consumption in L/100km runs the opposite way to MPG. A lower number is better — 5.0 L/100km is a frugal car, 10.0 L/100km is thirsty. If you learned to think in miles per gallon, or you're driving a UK import that displays MPG, switch the toggle and the figure converts across using imperial gallons.
Tax makes up a substantial share of what you pay at an Irish pump. Excise duty and VAT together mean that budget decisions and scheduled duty changes can shift prices sharply, sometimes overnight, independently of what crude oil is doing. That's part of why an average figure ages faster here than you might expect — always worth overriding with the price you're actually seeing locally.
If you're near the border, comparing against Northern Ireland means converting sterling pence per litre into euro per litre first. The gap moves with both the exchange rate and duty on either side, so it genuinely pays to check rather than assume one side is always cheaper.
FAQ
How do I calculate the fuel cost of a journey in Ireland?
Multiply your journey distance in kilometres by your car's consumption in litres per 100km, divide by 100 to get litres used, then multiply by the price per litre in euro. Enter those three figures above and the calculator handles the rest.
Is it cheaper to fill up in Northern Ireland?
It varies with the exchange rate and with excise duty on both sides of the border, so it is worth checking rather than assuming. Northern Ireland prices are quoted in pence per litre in sterling, the Republic in euro per litre, so you need to convert before comparing. For anyone living near the border the gap can be large enough to be worth planning around, but it swings in both directions over time.
Why is diesel more expensive than petrol in Ireland?
Diesel has historically been the cheaper of the two in Ireland, but that has not held consistently in recent years. Refining margins, international demand and changes to excise duty all move the two fuels independently, and diesel has at times overtaken petrol at the pump. Diesel cars generally use less fuel per 100km, which can still leave them cheaper to run overall.
What is L/100km and how does it compare to MPG?
Litres per 100km measures consumption, so a lower number is better — the opposite of MPG, where higher is better. Irish cars are normally rated in L/100km. If you think in MPG, switch the toggle above and your figure converts automatically using imperial gallons.
Does this include tolls or motor tax?
No — this is fuel cost only. Irish motorway tolls, the M50 barrier-free toll, motor tax, insurance and NCT costs are all separate and would need adding on top for a true cost of driving.
Why do Irish fuel prices change so suddenly?
Excise duty and VAT make up a large share of the pump price in Ireland, so budget decisions and scheduled duty changes can move prices overnight in a way that wholesale oil movements alone would not explain. Wholesale costs then feed through on top of that, usually over a week or two.