A freight carbon calculation needs a defined transport boundary, activity data and an appropriate emissions method or factor. Tonne-kilometres measure transport activity; they are not emissions by themselves. Multiplying activity by an intensity factor produces an estimate only within that factor’s stated scope.
Smart Freight Centre distinguishes measured operating data from estimates. Use that distinction when describing your own result: a calculator using assumed inputs is not a measured footprint for a specific carrier.
Define the activity
For a simple single-leg example, transport activity equals freight tonnes multiplied by distance in kilometres. A hypothetical two-tonne shipment moving 500 kilometres represents 1,000 tonne-kilometres.
For a multi-leg movement, calculate the activity associated with each relevant leg under the selected methodology. Record transfers or other operations separately where the method requires them. Do not multiply the total shipment weight by every leg if only part of the load travels on some legs.
Use a transparent illustrative factor
Assume, only to demonstrate arithmetic, an intensity of 0.10 kg CO₂e per tonne-kilometre. Then 1,000 tonne-kilometres × 0.10 = 100 kg CO₂e.
The factor is invented for the example. It is not a Canadian trucking average, a WTM figure or a recommended reporting factor. Replace it with an appropriate documented factor or verified service information before using the result in reporting.
Keep an assumptions register
| Field | Information to retain |
|---|---|
| Transport boundary | Which legs and activities are included |
| Freight quantity | Mass and measurement basis |
| Distance | Actual or estimated basis and source |
| Energy or intensity data | Measured, modelled or default |
| Factor source | Publication, version and applicable scope |
| Emissions boundary | What the factor includes and excludes |
| Allocation | How shared transport is attributed |
These details make a result interpretable. A number labelled only “carbon saved” does not reveal what was compared.
Distinguish total emissions from intensity
Smart Freight Centre’s reporting explanation distinguishes total emissions from emissions per unit of transport activity. Your total can change because you move more freight, even when intensity changes in another direction.
For a valid before-and-after comparison, keep boundaries and methods comparable. Do not claim a reduction merely because one estimate excludes a leg included in the other.
Start with better shipment data
Accurate weights, actual movements and traceable shipment records provide a better starting point than guessed distances and inconsistent quantities. They do not, on their own, establish verified energy use or emissions performance.
WTM’s freight and logistics services can be discussed around practical load planning and shipment records. This worksheet provides a transparent calculation method, not an environmental performance claim about WTM. Use appropriate primary information and the applicable reporting methodology when a formal footprint is required.
