Method: Freight activity is calculated in tonne-kilometres: Freight Activity = Cargo Mass × Distance Total freight emissions are then: CO₂e = Freight Activity × Emission Factor For example: 20 tonnes × 500 km = 10,000 tonne-km At an emission factor of: 80 g CO₂e/tonne-km emissions are: 10,000 × 80 = 800,000 g CO₂e = 800 kg CO₂e The calculator converts cargo weight internally to tonnes and distance to kilometres. Emission factors are intentionally editable because freight intensity can vary considerably with vehicle or vessel type, fuel, load factor, empty running, route, aircraft class, ship class, refrigeration, operational efficiency and accounting methodology. Use an emission factor expressed on a tonne-kilometre basis that is compatible with the transport mode and reporting boundary being assessed. This is an activity-based freight emissions calculation. It does not automatically include warehousing, packaging, terminals, transshipment, vehicle manufacturing or other logistics-chain emissions unless those impacts are incorporated in the emission factor used.