Carbon intensity is given as grams of CO2e per tonne-kilometre, and the unit in the denominator is the product of two numbers. The load is the actual mass of the goods including their own packaging; transport packaging that the carrier supplies, such as pallets and containers, is not counted. If the shipper has wrapped goods on a pallet, the pallet counts as part of the consignment.
Two kinds of distance are accepted: the great circle distance (GCD) and the shortest feasible distance (SFD). Air uses GCD; on the road SFD is much closer to the real distance, and the two are never mixed. The distance behind the intensity and the distance behind the tonne-kilometres must also be the same. Where only the actual distance exists, a distance adjustment factor (DAF) comes in:
| Mode | Distance type | Actual distance |
|---|---|---|
| Air | GCD | GCD + 95 km |
| Road | SFD | SFD + 5 % (factor 1.05) |
| Sea | SFD | SFD + 15 % (factor 1.15) |
On a multi-stop delivery round the distance is not the real route: the SFD from the hub to each delivery point is used, a consignment's tonne-kilometres are its SFD times its mass, and the round's total emissions are divided in proportion to those tonne-kilometres. Empty runs need no separate correction; the emissions calculation covers the whole round trip, empty legs included.
