Carbon tax on diesel by country — how carbon prices reach the cost of a litre

A carbon price reaches road diesel in two ways: as a carbon tax built into the fuel price, or through emissions trading at the fuel suppliers. A third design — emissions trading that covers only large emitters such as big ships and plants — does not price diesel at the pump. Of the 69 countries in our ROI calculator, 20 have an explicit carbon price on road diesel, counting the carbon component in France’s standard fuel-tax rate as the OECD does. In mid-October 2026, 19 of them charge it: Slovenia has suspended its levy until 14 December 2026. In the other 49 there is none at national level, though in the United States, California and Washington set one at state level. Per litre, the carbon price ranges from well under one euro cent in Japan to about 41 cents in Norway, before VAT — and wherever it applies, it follows the litres a fleet burns.

Rates and prices are as of mid-October 2026. Statutory rates usually change once a year; auction prices can change at each auction, and traded market prices can move continuously. For Germany and the EU’s second emissions trading system from 2028, see our analysis of EU ETS2 and Germany’s CO₂ price; for the rules by region, our overview of emission rules and carbon pricing.

1 · A carbon tax in the fuel price

The law sets the rate, usually per tonne of CO₂ or directly per litre, and it changes on fixed dates. It is collected from the companies that put fuel on the market and reaches a fleet through the pump price. Examples: Ireland charges €71 per tonne on diesel, which the law sets at €190.04 per 1,000 litres until 30 April 2027. Norway charges NOK 4.42 per litre of mineral oil. Japan’s climate change mitigation tax is JPY 289 per tonne, or JPY 760 per 1,000 litres of oil products. South Africa adds a carbon fuel levy of 23 cents per litre of diesel, and Mexico a fossil-fuel quota of MXN 0.215 per litre.

Sweden and Slovenia show that a statutory rate can move quickly. Sweden’s CO₂ tax on diesel is temporarily SEK 0.411 per litre until 30 November 2026 and returns to SEK 2.811 per litre from 1 December 2026; Slovenia has suspended its CO₂ levy on diesel until 14 December 2026 and charges €0.0833 per litre again from 15 December. France has no separate carbon tax: its fuel-tax rates were raised between 2014 and 2018 on the basis of an informal carbon component that reached €44.60 per tonne, and most rates have been held at that level since. Following the OECD’s method, we count that component at the standard rate only.

2 · Emissions trading at the fuel suppliers

The suppliers must hold an allowance for every tonne of CO₂ in the fuel they sell. The number of allowances is capped and the price is set by auctions or trading, so it moves. Every 2026 auction in Germany’s national scheme closed at €65 per tonne, the top of its legal corridor; Austria fixes €55 per tonne for 2026 and 2027. New Zealand’s emissions trading scheme covers liquid fossil fuels, including diesel, upstream — when refined products leave the refinery or are imported; its monthly market index stood at NZ$50.21 per unit on 30 September 2026. In the United States, California and Washington run such systems at state level: their latest auctions cleared at $32.48 (August 2026) and $39.50 (September 2026) per tonne. Washington’s June auction had cleared at $64.56, which shows how far a market price can move in one quarter. From 2028, the EU’s ETS2 adds such a system for road fuel across the EU.

3 · Systems for large emitters only — not diesel at the pump

Some systems cover ships or plants directly, not fuel at the pump. The EU’s emissions trading system covers cargo and passenger ships of 5,000 gross tonnage and above: all emissions on voyages between EEA ports and while in EEA ports, and half on voyages between an EEA and a non-EEA port, subject to statutory exemptions. From 1 July 2026, the UK’s system covers ships of that size on voyages between UK ports and while in UK ports, subject to its own exclusions. Singapore’s carbon tax applies only to facilities emitting 25,000 tonnes of CO₂e or more, and expressly not to vehicles or to fuels subject to excise duty. Australia’s Safeguard Mechanism covers only facilities with more than 100,000 tonnes a year. These systems do not themselves put a carbon price on road diesel; a separate road-fuel scheme may still apply in the same country.

No explicit carbon price on road diesel

In 49 of the 69 countries we track, road diesel carries no explicit carbon price at national level. Among them: the United Kingdom, where fuel duty is a general excise duty and the UK ETS does not cover road transport; the United States at federal level, with California and Washington as the exceptions above; India; and Canada, where the federal fuel charge has been zero since 1 April 2025. Provincial schemes are separate and not covered here. Fuel duty, where it exists, matters for the fuel bill, but it is not a carbon price, and we do not count it as one.

How the euro column is calculated. Where the law sets an amount per litre, we use it. Where the price is per tonne, we multiply by 2.62818 kg of CO₂ per litre of mineral diesel, the UK government’s 2026 conversion factor, which our calculator also uses; for Germany we use the German standard value of 2.676 kg. Local currencies are converted at the European Central Bank’s reference rates of 5 October 2026; the Argentine and Colombian pesos via the US dollar at the official reference rates of 2 and 3 October 2026. National factors, biofuel blending and exemptions make the actual amount per litre differ slightly; the rate as set is the figure to rely on.

Pass-through. Where suppliers carry the obligation, the carbon cost reaches a fleet only to the extent that they pass it on in the fuel price; how much they pass on, and when, is their pricing decision.

Refunds for professional users. In France, goods vehicles of 7.5 tonnes and above, coaches and buses can claim a partial refund of the fuel tax on diesel; the OECD does not count a carbon component in that reduced rate. In South Africa, the diesel refund available to some users never includes the carbon fuel levy.

Biofuel blending. Several countries charge the carbon price only on the fossil part of a blend — Denmark, for example, sets lower rates for diesel containing biofuel, and in Germany the DEHSt notes that blending lowers the charge — so blended diesel can carry a little less than the table shows. Not every country does this.

Other uses. Fuel for uses other than road transport is often treated differently. In Germany, for example, tax-exempt fuel for commercial shipping carries no national CO₂ price, while farm diesel keeps it despite its energy-tax relief. Off-road machinery, farm diesel and generators can be treated differently from road fuel in the same country — our ROI calculator distinguishes these uses country by country.

1. Litres by country and use. Fuel cards and depot records give you the litres; which use falls under which scheme differs by country.
2. The rate. Where the law sets an amount per litre, multiply the litres by it. Where the price is per tonne, multiply the litres by about 2.63 kg of CO₂ per litre of mineral diesel, convert to tonnes and multiply by the price.
3. The trend, not just today’s rate. Statutory rates usually change once a year and are often announced in advance — Ireland, Denmark and Lithuania, for example, have already set their rates for 2027. Auction prices can change at each auction, and traded market prices can move continuously.
4. Refunds and exemptions that apply to your vehicles and uses, as above.
5. Before or after VAT. If your company recovers input VAT, the figure before VAT is the one that matters. This is not tax advice.

Our ROI calculator does this for all 69 countries and the US states, with your own fuel volumes and prices, and shows the carbon price where it reaches the fuel bill.

Wherever it applies, a carbon price on fuel turns into a cost per litre, so a fleet’s carbon cost moves with the litres it burns. Route planning, driver training, maintenance, tyres and vehicle choice all work on that number. An air-filter treatment such as NanoEFX is another option to test, measured on your own engines and duty cycles. It is not a fuel additive, not an oil additive, not an ECU remap and not a retrofit; whether it lowers fuel consumption on your vehicles is something to measure, not to assume, and results depend on engine type, duty cycle, filter condition and correct application.

Our guide to measuring fleet fuel consumption sets out how to establish a baseline, and the pilot programme runs the comparison on your own fleet.