How to Calculate the Carbon Footprint of Your Food Waste

Food waste isn't just a financial problem—it's one of the largest contributors to climate change. When you throw away food, you're throwing away all the emissions that went into producing it: farming, processing, transport, refrigeration. Plus the methane released when it decomposes in landfill.

FAO estimates food waste accounts for 8-10% of global greenhouse gas emissions. That's more than the aviation industry.

If you're reporting on sustainability or just want to understand your operation's impact, you need to know how to calculate the carbon footprint of your waste.

The Basic Calculation

The carbon footprint of food waste is calculated by multiplying the weight of waste by emission factors specific to each food type.

Carbon footprint (kg CO2e) = Waste weight (kg) × Emission factor (kg CO2e/kg food)

The emission factors vary significantly by food type because different foods have different production impacts:

• Beef: 27-60 kg CO2e per kg (depending on production method)
• Lamb: 24-39 kg CO2e per kg
• Cheese: 13-21 kg CO2e per kg
• Pork: 7-12 kg CO2e per kg
• Poultry: 6-9 kg CO2e per kg
• Fish: 5-13 kg CO2e per kg
• Eggs: 4-5 kg CO2e per kg
• Rice: 3-4 kg CO2e per kg
• Vegetables: 0.5-2 kg CO2e per kg
• Fruits: 0.5-1.5 kg CO2e per kg

These are production-only figures. Add processing, transport, and retail and they increase by 10-30% depending on the supply chain.

Why Composition Matters

Ten kilos of wasted beef has roughly 40 times the carbon impact of ten kilos of wasted vegetables. This is why weight-based waste metrics alone can be misleading from an environmental perspective.

A kitchen might reduce total waste weight while increasing carbon impact if the reduction comes from vegetables and the remaining waste is protein-heavy. Or vice versa—you might have stable waste weight but falling carbon footprint if you're wasting less meat.

Tracking waste composition gives you a much more accurate picture of environmental impact than total weight alone.

Adding Disposal Emissions

When food waste goes to landfill, it decomposes anaerobically and releases methane—a greenhouse gas about 25 times more potent than CO2 over a 100-year period. This adds approximately 0.5-1 kg CO2e per kg of food waste on top of the production emissions.

If your waste is composted or sent to anaerobic digestion, disposal emissions are much lower (and can even be negative if the biogas is captured and used for energy). This is why waste destination matters for your footprint.

Landfill: Add ~0.7 kg CO2e per kg waste Composting: Add ~0.1 kg CO2e per kg waste Anaerobic digestion: Can be neutral or negative

Practical Calculation Steps

To calculate your operation's food waste carbon footprint:

Step 1: Categorise your waste. You need to know roughly what you're throwing away. At minimum, break it into proteins (with beef/lamb separated if possible), dairy, grains, vegetables, and fruit.

Step 2: Apply emission factors. Multiply each category by its emission factor. Use the figures above or look up more specific factors from sources like the WRAP food waste database.

Step 3: Add disposal emissions. Based on where your waste goes, add the appropriate disposal factor.

Step 4: Sum everything. Total CO2e gives you your carbon footprint from food waste.

An Example

A hotel kitchen with monthly food waste of:

• 50kg beef waste × 45 = 2,250 kg CO2e
• 100kg mixed protein waste × 8 = 800 kg CO2e
• 30kg dairy waste × 15 = 450 kg CO2e
• 200kg vegetable waste × 1 = 200 kg CO2e
• 50kg grain waste × 2 = 100 kg CO2e
• Disposal (430kg × 0.7) = 301 kg CO2e

Total: 4,101 kg CO2e per month, or ~49 tonnes CO2e annually

That's equivalent to about 10 cars' annual emissions—just from food waste.

Using the Data

Once you have a baseline, you can:

• Set reduction targets. A 50% reduction in waste might deliver 40% or 60% carbon reduction depending on what you're wasting less of.
• Prioritise interventions. If beef waste is driving most of your footprint, focus there first.
• Report credibly. Sustainability reports increasingly expect carbon data, not just weight-based metrics.
• Communicate impact. "We've reduced food waste carbon emissions by X tonnes" is more meaningful than "we've cut waste by Y kilos."

The Bigger Picture

Food waste reduction is one of the most effective climate actions any hospitality business can take. Project Drawdown ranks reducing food waste as one of the top solutions for addressing climate change—ahead of solar power and electric vehicles.

The financial case is clear (waste costs money), but the environmental case is equally compelling. Reducing your food waste is reducing your carbon footprint in a direct, measurable way.

Calculate your potential cost savings, or request a sustainability assessment that includes carbon footprint analysis.