What does cradle-to-gate mean?

Cradle-to-gate counts emissions from raw-material extraction through to the factory gate, before distribution and use. It excludes transport to customers, the use phase, and end-of-life, which a full cradle-to-grave assessment would add.

Where do the emission factors come from?

The material and process factors are simplified averages drawn from public LCA databases such as Ecoinvent summaries, the ICE database, and DEFRA factors. They are order-of-magnitude estimates for early design decisions, not certified declarations.

How does the energy source change the result?

Processing emissions scale with the carbon intensity of the electricity you use. A grid-average mix is far higher than renewable power, so switching the energy source can cut the processing component severalfold without changing materials.

Can I use this for a verified PCF declaration?

No. A declaration to ISO 14067 or PAS 2050 needs primary supplier data and a verified factor set. This tool is for screening and design trade-offs, helping you find the biggest levers before commissioning a formal assessment.

Why is recycled material lower?

Recycled feedstocks avoid most of the energy-intensive primary extraction and refining steps, so their embodied-carbon factor is typically a fraction of the virgin equivalent. Choosing recycled aluminium over virgin is one of the largest single reductions available.

What is the Product Carbon Footprint Estimator?

Add material inputs, a manufacturing process, an energy source, and packaging to compute a cradle-to-gate product carbon footprint in kg CO2e per unit using simplified LCA emission factors. For product designers making early-stage environmental decisions. It runs free in your browser on Gera Tools, with nothing uploaded.

Product Carbon Footprint Estimator

Name: Product Carbon Footprint Estimator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

This estimator builds a cradle-to-gate product carbon footprint (PCF) from the bottom up: every kilogram of material carries an embodied-carbon factor, the manufacturing process adds energy-related emissions, and packaging is counted too. It is a screening tool for designers who want to find the biggest carbon levers before commissioning a formal life-cycle assessment.

How it works

The footprint is the sum of three contributions:

materials   = Σ (material mass × embodied factor)
processing  = total material mass × process energy (kWh/kg) × grid factor (kgCO2e/kWh)
packaging   = packaging mass × packaging factor
total PCF   = materials + processing + packaging   (kg CO2e per unit)

Material embodied factors vary enormously: virgin aluminium is around 11 kg CO2e per kg while recycled aluminium is near 2, and engineering plastics sit around 3 to 6. The processing term multiplies energy intensity by the carbon intensity of your chosen electricity source, so a renewable mix dramatically shrinks it.

Why materials usually dominate

For most manufactured goods, the materials component is the largest single contributor to cradle-to-gate emissions — often 60–90% of the total. This is why material substitution decisions made early in design have far greater leverage than later manufacturing or packaging tweaks.

The biggest material contrasts to know:

Virgin vs. recycled aluminium — virgin primary aluminium requires energy-intensive smelting and typically carries an embodied factor in the range of 8–11 kg CO2e/kg, while recycled (secondary) aluminium needs only a fraction of that energy and sits around 1–2 kg CO2e/kg. Switching from virgin to recycled aluminium is one of the most impactful single decisions in metal product design.
Steel variants — basic oxygen furnace (BOF) steel is roughly 1.9–2.5 kg CO2e/kg; electric arc furnace (EAF) steel using recycled scrap is around 0.4–0.8 kg CO2e/kg.
Plastics — engineering polymers vary considerably, generally in the range of 2–6 kg CO2e/kg, with bio-based alternatives sometimes lower and high-performance polymers (PEEK, PPS) higher.
Wood and natural fibres — often have lower embodied carbon than metals and plastics, but figures depend heavily on whether the carbon sequestered in the material during growth is accounted for (which cradle-to-gate typically does not credit).

The energy source multiplier

Once materials are chosen, the next biggest lever is the electricity used in manufacturing. The grid factor in the calculation is the carbon intensity of your electricity source measured in kg CO2e per kWh. A coal-heavy grid might carry a factor above 0.7, a gas-dominated mix around 0.4, and a predominantly renewable supply below 0.1. For a process-intensive product, switching to a renewable supply or a green-tariff contract can cut the processing component by 80% or more.

Illustrative example

For a 0.8 kg part made from virgin aluminium, injection-moulded on a grid-average electricity supply with 0.05 kg of cardboard packaging:

Materials: 0.8 kg × ~11 kg CO2e/kg ≈ 8.8 kg CO2e
Processing: modest contribution from the moulding step
Packaging: 0.05 kg × cardboard factor ≈ small contribution
Total: roughly 9–10 kg CO2e per unit

Switching to recycled aluminium drops the materials term to roughly 0.8 × ~2 = 1.6 kg CO2e, cutting the total by around half — without changing the design or the manufacturing process at all. This is why material choice is the first question in any PCF reduction effort.

Limitations and next steps

This tool uses simplified average factors from public life-cycle databases. It is appropriate for:

Early design trade-offs — comparing material options before prototyping.
Hotspot identification — seeing which phase dominates the footprint.
Stakeholder communication — rough-order estimates for internal or early-stage sustainability discussions.

It is not appropriate for a certified PCF declaration or an Environmental Product Declaration (EPD). Those require primary supplier-specific emission data and a third-party verified factor set aligned to ISO 14067 or PAS 2050. Once the design is settled and supplier relationships are established, a formal assessment can use the real emission factors from your specific supply chain.