Menu Carbon Footprint Calculator

For each ingredient, multiply its weight in kilograms by its emission factor (kg CO2e per kg of that ingredient), then add the ingredients together and divide by the number of portions. The result is kg CO2e per serving. The calculator does this for you and also flags which ingredient contributes the most, which is almost always the lever with the biggest impact.

An emission factor is the average greenhouse-gas emissions associated with producing one kilogram of an ingredient, expressed in kg CO2e (carbon dioxide equivalent, which rolls methane and other gases into a single number). Beef sits very high (often 20-30 kg CO2e/kg), while vegetables, bread and legumes are typically under 2. These are indicative averages: real values depend on the production source, farming methods and region, so treat the output as an estimate for comparison rather than a certified figure.

Kilograms of CO2e are abstract for most people. Dividing the per-portion footprint by roughly 0.12 kg CO2e per kilometre (a typical petrol car) turns it into a relatable distance, which is useful on menus and in staff training. It is a communication device, not a precise audit, so the comparison should be presented as approximate.

Animal proteins, and beef and lamb in particular, almost always dominate because ruminant livestock emit methane and need a lot of land and feed. In a typical meat dish the protein can account for 80-95% of the total. That is why the calculator highlights the top contributor: swapping or reducing one high-impact ingredient often cuts the footprint far more than changing everything else.

They are indicative estimates. Published emission factors vary between databases and depend heavily on the source, season and region, and the calculator does not model transport, cooking energy or packaging unless you include them. Use it to compare dishes, identify hotspots and guide menu decisions rather than to make absolute environmental claims.