Turning a fuel receipt into emissions: the litres-then-factor method

A fuel receipt is one of the most common pieces of evidence behind a GCC fleet's emissions — and one of the most misread. It tells you what was paid, not what was burned. To report emissions you need litres; the receipt gives you a total in local currency. Bridging that gap correctly is the difference between a number you can defend and a guess.

The two-step method

There are two moves, in order: turn the amount paid into litres using the pump price in force, then turn litres into emissions using an emission factor.

• Cost → litres: divide the amount on the receipt by the pump price for that country, grade and month.
• Litres → emissions: multiply the litres by the emission factor for that fuel.

Why the price has to be the right one

This is where generic tools fall down. Fuel prices in the GCC differ by country and by grade, and several change month to month. Use last year's price, or a neighbouring country's, and you quietly distort the litres — and therefore the emissions. The price you apply must be the one in force that month, for that country, for that exact grade.

A worked example, with illustrative figures: a receipt shows 500 in local currency for diesel. If the pump price that month was, say, 0.79 per litre, that's about 633 litres. Change the price and the litres change with it — which is exactly why the price source matters as much as the arithmetic.

Applying the factor

With litres in hand, multiply by the emission factor for that fuel — a value taken from a maintained library rather than typed from memory. The point of a shared library is consistency: every team applies the same factor, so two people reporting the same activity reach the same number instead of two.

Keep the trail

The point isn't only the answer; it's being able to show how you reached it. A defensible fleet-fuel figure can be traced back to the receipt it came from, the price applied that month, and the factor used. When an assuror asks, the whole chain is one click away — not a folder someone has to reconstruct under deadline.

This is exactly what Susmatic ESG automates: it reads the receipt, applies the maintained GCC price for that country and grade to derive litres, applies the factor from the Emission Library, and keeps every step attached to the record.