tonnemile

Ton­ne-mile, or ton-mile, is a unit of transport work used in freight logistics to quantify the amount of goods moved over a distance. It is defined as the movement of one tonne of payload by one mile. In metric terms, the equivalent unit is the tonne-kilometre (tkm), where moving one tonne by one kilometre equals one tkM. The relationship between the two is 1 tonne-mile = 1.60934 tonne-kilometres, and conversely 1 tonne-kilometre = 0.621371 tonne-miles.

Use of tonne-miles is common in analyzing freight throughput, energy intensity, and service levels across modes such as rail, road, and shipping. By normalizing cargo quantity to distance, it allows comparisons of workload and utilization across routes and times, independent of exact vehicle types or capacities. It also aids in planning and performance benchmarking, for example in evaluating fuel efficiency per unit of transport work and in cost-per-tonne-mile analyses.

Limitations and context are important: tonnage-work metrics reflect volume and distance but not the specific energy consumed, route geography, or vehicle energy efficiency. They also do not account for empty backhauls, loading factors, or time-related costs. As international reporting increasingly uses metric units, tonne-kilometres are often preferred in official statistics, while ton-miles remain common in certain regions and industry segments that follow customary units.

See also: tonne-kilometre, ton-mile, freight metrics, transport economics.