Meat vs Plant Emissions Comparison Calculator

Emissions figures represent kilograms of CO₂ equivalent (CO₂e) per kilogram of protein, drawing on life-cycle assessment (LCA) data that covers farming, feed production, processing, and transport. The calculator multiplies your weekly serving weight by 52 weeks and by the food's emission factor to produce an annual figure. All values are global averages compiled from peer-reviewed research including studies published by Oxford University and the IPCC.

Cattle produce methane during digestion (enteric fermentation), a greenhouse gas roughly 28 times more potent than CO₂ over 100 years. Beef also requires far more land and feed to produce the same amount of protein compared to pork or chicken, multiplying its total carbon footprint. Lamb has an even higher footprint per kilogram of protein for similar reasons.

Greenhouse gases — primarily CO₂, methane (CH₄), and nitrous oxide (N₂O) — trap heat in the atmosphere, driving climate change. Agriculture accounts for around 26% of global greenhouse gas emissions, with livestock farming responsible for the largest share. Food production choices can therefore have a meaningful impact on an individual's total carbon footprint.

The car-miles figure translates your annual CO₂ savings into a familiar reference point. The average passenger car emits about 404 grams of CO₂ per mile driven (US EPA estimate). Dividing your total savings by this rate gives the equivalent number of driving miles avoided — helping you visualise the real-world impact of a dietary change.

The calculator defaults to 100 g (3.5 oz) per serving, which aligns with standard nutritional portion sizes used in most dietary research. You can adjust to 75 g, 150 g, or 200 g using the serving size selector to better match your actual plate. Protein and emissions scale proportionally with serving weight.

In most cases, yes — plant-based proteins emit significantly less CO₂e per kilogram of protein than animal products. However, rice carries a relatively high footprint due to methane released from flooded paddy fields, and some nuts can be water-intensive. The biggest gains come from replacing beef, lamb, and cheese with legumes, tofu, or lentils.

No. Emission factors vary significantly by country depending on farming methods, energy sources, feed composition, and land-use practices. For example, beef raised on deforested Amazon land carries a much higher footprint than pasture-raised beef in some European countries. The figures used here are global averages, intended for general comparison rather than country-specific precision.

A mature tree absorbs approximately 21 kg of CO₂ per year on average, though this varies by species and age. The 'trees equivalent' output divides your annual CO₂ savings by 21 to show how many trees would need to grow for a year to sequester the same amount — a useful way to appreciate the scale of dietary impact without planting a forest.