Food Miles Calculator (Supply Chain)

Food miles measure the distance food travels from where it is produced to where it is consumed. The concept helps quantify the environmental impact of transporting food — the more miles traveled, especially by air, the higher the associated carbon emissions and environmental cost.

Different transport modes produce very different levels of CO₂ per tonne-mile. Air freight emits roughly 1.013 kg CO₂ per tonne-mile, while sea freight emits only about 0.010 kg — making air nearly 100 times more polluting. Road sits in the middle at around 0.161 kg, and rail is the cleanest land option at approximately 0.028 kg CO₂ per tonne-mile.

Long food supply chains contribute to greenhouse gas emissions, air pollution, and climate change. Air-freighted foods are particularly damaging due to the high altitude at which emissions are released, amplifying their warming effect. High food miles also often correlate with more packaging and refrigeration energy use.

The most effective step is buying locally and seasonally produced food. Shopping at farmers' markets, joining a local CSA (Community Supported Agriculture) box scheme, and choosing foods transported by sea or rail rather than air all make a meaningful difference. Growing your own vegetables, even a small herb garden, eliminates food miles entirely.

Not necessarily. An organic product imported by air from the other side of the world can have a far higher carbon footprint than a conventionally grown local equivalent. When weighing up environmental impact, transport emissions often outweigh farming method differences, so proximity matters as much as production method.

This calculator uses standard emission intensity factors (kg CO₂ per tonne-mile) for each transport mode, multiplied by the distance traveled and the weight of the food shipment. The emission factors are based on widely used freight logistics benchmarks: air ≈ 1.013, road ≈ 0.161, sea ≈ 0.010, and rail ≈ 0.028 kg CO₂ per tonne-mile.

Yes — most food goes through a multi-modal supply chain. For example, fruit from Chile might travel by truck from the farm to a port, then by cargo ship across the ocean, then by train or road to a distribution center, and finally by van to a supermarket. This calculator lets you enter distances for all four modes to capture the full journey.

The emissions rating gives a simple 1–5 score summarizing the environmental impact of the food's journey: 1 (Very Low) means minimal emissions typical of local produce, while 5 (Very High) indicates a long-distance, air-heavy supply chain with significant climate impact. It's designed to give you a quick sense of how your food scores compared to typical supply chains.