Which emission factors does this use?

It uses DEFRA UK Government greenhouse gas conversion factors for materials production, expressed in kg CO2e per kg of material. Virgin and recycled grades have separate factors, and the tool blends them by your recycled content percentage.

How does recycled content reduce the footprint?

Recycled material avoids most of the energy-intensive primary production step. The tool blends the virgin and recycled factors in proportion to your recycled content, so 50 percent recycled PET sits halfway between the virgin and fully recycled values.

Can I model a multi-material pack?

Yes. Add one row per component — for example a glass bottle, an aluminium cap, and a paper label — and the tool totals them. This is essential because the lightest component by weight can still dominate if it is a high-impact material like aluminium.

Why is aluminium so high per kilogram?

Primary aluminium smelting is extremely energy intensive, around 9 to 12 kg CO2e per kg for virgin metal. Recycled aluminium is far lower, near 0.5 kg CO2e per kg, which is why high recycled content is the single biggest lever for metal packaging.

Does this include transport or end-of-life?

No. This covers cradle-to-gate material production only. Transport to your site, filling, distribution, and disposal or recycling at end of life are separate stages. For a full lifecycle assessment, add those stages on top of this material footprint.

Packaging Carbon Footprint Calculator

Packaging is often a brand’s most visible and most measurable emissions source, and the choice of material matters more than weight: a few grams of aluminium can outweigh a heavy paper carton. This calculator totals the cradle-to-gate carbon of a multi-component pack and scales it to your annual volume.

How it works

Each component blends a virgin and a recycled emission factor by its recycled content, then the components are summed:

blended factor = virgin × (1 − recycled%) + recycled × recycled%
component CO2e  = weight (kg) × blended factor
per-unit CO2e   = sum of all components
annual CO2e     = per-unit CO2e × annual volume

Because recycled grades carry far lower factors, raising recycled content shifts the blended factor toward the cleaner value — the simplest way to cut a pack’s footprint without redesigning it.

Example and tips

A 330 ml glass bottle weighs about 200 g; at a virgin glass factor near 0.9 kg CO2e/kg that is 0.18 kg per unit, dropping to about 0.12 kg at 50 percent recycled cullet. Add a 2 g aluminium cap (high factor) and a 1 g paper label and you have a full composite footprint. Across a million units, shifting glass from 0 to 60 percent recycled content saves tens of tonnes of CO2e a year. Always check the highest-impact material first — usually metal or virgin plastic — not the heaviest one.