Fuel Price Breakdown Simulator: What a Litre Costs in France

On a litre of French fuel, more than half the price does not depend on the barrel: the excise is a fixed amount per litre, and the 20% VAT applies to the product and to the excise itself. This simulator makes that mechanism something you can handle. Set Brent, the euro-dollar rate and the refining and distribution margins, and watch the litre bar rebuild segment by segment, for diesel or SP95 gasoline (E5/SP98).

The default values reproduce the 3 July 2026 decomposition documented in our analysis of the French pump price, decomposed: a litre of SP95 at €1.873, of which 53.5% is tax.

What the tool computes

The pre-tax product adds three components: Brent converted into euros per litre (one barrel = 159 litres), the refining margin, and distribution costs — transport, retailer margin, energy-savings certificates, biofuel blending. On top sits the energy excise, fixed per litre: €0.6075 for diesel, €0.6902 for SP95 (the E5/SP98 rate), 2026 schedules outside Corsica (DGEC). The 20% VAT then applies to the sum of product and excise — a tax levied on a tax. At the defaults, SP95 comes to €1.873 per litre (53.5% tax) and diesel to €1.863 (49.3%), the UFIP national averages of 3 July 2026.

One methodological point: no official weekly series isolates the refining margin from the rest of the price. The default shown is therefore estimated as a residual, so the total matches the observed average price. How that margin forms — and why it weighs more than the barrel in oil profits — is covered in the dedicated analysis of refining margins.

What the Brent slider shows

Push Brent to $150: a litre of SP95 rises to €2.409, but the tax share falls to 45.3%. Bring it down to $20: diesel drops to €1.542 and the fiscal share climbs to 56.1%. The tax share rises when the barrel falls — a proportion effect, not a tax increase: the fixed floor simply weighs more in a smaller total. This is also why a move in crude never passes through in full: it only acts on the “product” fraction, less than half the price. For contrast, the US retail price — where taxes are about 18% — tracks the barrel far more closely; the underlying series are in the US regular gasoline retail price and US diesel retail price datasets.

Limits

The tool works on national average prices: differences between stations come from distribution and competitive density, not from taxation, which has been national and uniform outside Corsica since the regional modulation was abolished on 1 August 2025. E85 and LPG, subject to specific reduced excise rates, are out of scope. And the decomposition is accounting-based and instantaneous: it says nothing about how fast a move in crude reaches the pump — that pass-through asymmetry is measured in our test on French data.

Frequently asked questions

Why does the pump price fall less than the barrel?

Because the component that tracks crude — the refined product — is less than half the French price. The excise, fixed per litre, does not move; only the VAT levied on the product varies at the margin. A 10% drop in Brent therefore cuts the litre by only a few percent, which the slider makes directly visible.

Does the state collect more when the barrel rises?

Not through the excise, which is an amount per litre rather than a share of the price: a more expensive barrel leaves its revenue unchanged, or lower if consumption falls. Only VAT, which is proportional, rises mechanically with the pre-tax price — a distinction the public debate frequently conflates.

Go deeper

• The full decomposition of the French litre and the US comparison: where your fuel money goes.
• Do pump prices rise faster than they fall? The asymmetry measured on French data.
• Upstream mechanics: refining margins as the hidden driver of oil profits.
• Your own exposure: fuel burden calculator.
• The framework: commodity price formation.

Last updated — 12 July 2026