Is your energy surcharge calculated correctly?

Enter your contract formula, the indices for the period and the rate applied on your invoice. You get the gap straight away, in points and in euros. The same calculation covers contracts indexed on gas or electricity.

The calculation runs entirely in your browser. No data is sent, stored or kept. No sign-up is required.

Your invoice and your formula

Indexed energy

The formula is the same whatever the energy: only the reference index changes.

Base amount excluding VAT for the period

The transport amount before the energy surcharge, for one shipment or for the whole month.

Energy share set in the contract

The share of the price treated as sensitive to energy costs. For diesel, most often between 20 and 35%.

Base index (contractual reference)

The index the contract sets as the starting point for indexation. For professional diesel, the indices published by the Comité National Routier are the ones most commonly used in France. Others exist: use the one your contract names.

Index for the invoiced period

The index published for the month the invoice covers. For professional diesel, the indices published by the Comité National Routier are the ones most commonly used in France. Others exist: use the one your contract names.

Surcharge rate applied on the invoice

The surcharge percentage the carrier charged you.

How the calculation works

Surcharge rate = energy share × (period index − base index) ÷ base index

This is the most widespread indexation formula in road transport contracts, whatever the energy. It applies the relative movement of the index to the fraction of the price treated as sensitive to energy costs.

If your contract uses a different mechanism — a rolling average over several months, a trigger threshold, quarterly revision, indexation on an observed price rather than an index — the result above is only an approximation. Check the clause before raising it with your carrier.

Which index should you use?

The one your contract names, and only that one: changing the index changes the result. Indices are many, and depend on the energy as much as on the contract.

For professional diesel, the indices published by the Comité National Routier are the ones most commonly used in France. Others exist, published by trade federations, by energy suppliers or by INSEE, and some contracts use a jointly observed price rather than an index.

CarrierBridge redistributes no index. You enter the value you have looked up, and it never leaves your browser.

This tool gives an indication of the calculation. It is neither legal advice nor a contractual analysis, and it does not certify that an invoice is correct. A gap found is a point to raise with your carrier.

Twelve months of invoices, every carrier, in one go

This calculator handles one line at a time. In CarrierBridge you enter your formula once — for each energy and each contract — and the gap is tracked automatically, month after month, carrier by carrier, alongside your rate sheets and ancillary charges.

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