What goes into a product carbon footprint?
A PCF adds up the emissions from each stage of a product's life:
- Raw materials — extracting cotton, drilling oil for plastic, mining metals.
- Manufacturing — energy used to weave, mould, assemble. This depends heavily on the country's electricity grid.
- Transport — getting raw materials to the factory and finished goods to the customer. Sea freight is ~40× cleaner per tonne-km than air.
- Use phase — energy a product consumes while in service (electronics, appliances, cars).
- End of life — landfill, incineration or recycling.
Most product carbon footprints stop at "cradle-to-gate" (raw materials + manufacturing + inbound transport), because the manufacturer controls those stages and that's what most B2B buyers ask for. Full lifecycle ("cradle-to-grave") is required for consumer-facing labels and Digital Product Passports.
Worked example 1 — a cotton T-shirt
A 200 g conventional cotton T-shirt, made in China, shipped to Europe:
- Material: 0.2 kg × 8.0 kg CO₂e/kg cotton = 1.60 kg CO₂e
- Manufacturing: 0.2 kg × 1.0 kWh/kg × 0.555 kg CO₂e/kWh (China grid) = 0.11 kg CO₂e
- Sea freight (9,000 km): 0.0002 t × 9,000 km × 0.016 kg/t·km = 0.03 kg CO₂e
- Total ≈ 1.74 kg CO₂e per T-shirt
An organic cotton version drops the material factor from 8.0 to 3.5 kg/kg — halving the total. Made in France instead of China, the manufacturing emissions fall by 80% because the French grid is 6× cleaner than China's.
Worked example 2 — a 500 ml PET bottle
- 10 g of virgin PET × 2.5 kg CO₂e/kg = 25 g CO₂e
- Manufacturing (forming the bottle, mostly already in the PET factor) ≈ 3 g CO₂e
- Short road freight ≈ 2 g CO₂e
- Total ≈ 30 g CO₂e per bottle
Switching to recycled PET (rPET) drops it to ~14 g — more than half.
Worked example 3 — a smartphone
A new flagship smartphone weighs ~180 g but its footprint is dominated by tiny components:
- Printed circuit board (~25 g): 0.025 × 35 = 0.88 kg CO₂e
- Lithium-ion battery (~40 g): 0.040 × 75 = 3.00 kg CO₂e
- Aluminium chassis (~30 g virgin): 0.030 × 11 = 0.33 kg CO₂e
- Glass, plastic, copper, packaging: ~5 kg CO₂e
- High-intensity assembly (electronics): + ~6 kg CO₂e
- Freight (air, 8,000 km, 0.2 kg): 0.96 kg CO₂e
- Total ≈ 60–80 kg CO₂e for a new smartphone
Use phase adds another 10–20 kg over the device's life. The most powerful thing you can do as a consumer is keep your phone for longer: a phone used for 4 years has half the per-year footprint of one replaced every 2 years.
Calculate any product in 30 seconds
Our free Quick PCF calculator uses peer-reviewed cradle-to-gate factors for cotton, polyester, plastics, metals, paper, wood, electronics and more — drawn from DEFRA, ecoinvent, worldsteel, PlasticsEurope and the IAI. You pick the category, material, weight, manufacturing country and freight mode; we calculate the rest.
For SMEs answering supplier questionnaires (CDP, CSRD, CBAM), an ISO 14067-aligned version is in early access — same engine, but with a full bill-of-materials editor and a branded PDF you can send to your buyer.