How to calculate the carbon footprint of a garment
Updated 4 October 2026 · 6 min read
In short. The carbon footprint of a garment is the sum of three parts:
- Fibres: fibre weight × fibre emission factor
- Processing: energy used at each stage × factor of the country where it happens
- Transport: tonnes × kilometres × factor of the transport mode
The result is expressed in kg CO₂e per garment.
What a garment’s carbon footprint is
It is the amount of greenhouse gases emitted to make a garment, expressed in kg of CO₂ equivalent (CO₂e). “Equivalent” means that other greenhouse gases, such as methane and nitrous oxide, are converted into the amount of CO₂ that would have the same effect on the climate.
For a textile company the most useful scope runs from raw materials until the garment leaves the factory: this is the part where producers and suppliers have data and can act. Distribution, use (washing, drying) and end of life are added in a full life cycle study.
The stages to include
- Fibres: growing or producing the raw fibre (cotton, wool, polyester, viscose…).
- Spinning: turning fibre into yarn.
- Weaving or knitting: from yarn to fabric.
- Wet processing: dyeing, finishing and printing. It uses a lot of heat, often from natural gas.
- Garment making: cutting and sewing.
- Transport between suppliers, up to the factory that makes the garment.
What data you need
| Stage | Data | Where to find it |
|---|---|---|
| Fibres | Garment weight and composition (for example 95% cotton, 5% elastane) | Tech pack, care label |
| Processing | kWh of electricity and m³ of gas per garment, country of each supplier | Utility bills and meters, supplier questionnaire |
| Transport | Mode and kilometres of each leg | Shipping documents, supplier addresses |
If a department only knows its yearly energy use, divide it by the number of garments produced in the same year.
The formula
- Fibres = kg of fibre × fibre factor (kg CO₂e per kg), increased by production waste.
- Processing = kWh × the country’s electricity factor + m³ of gas × the natural gas factor.
- Transport = tonnes carried × km × factor of the mode (sea, truck, air, rail).
The electricity factor varies widely between countries: the same spinning step can emit twice as much, or half as much, depending on where it happens. That is why each supplier’s country matters as much as the kWh.
An example: a 180 g cotton T-shirt
| Stage | kg CO₂e |
|---|---|
| Fibres | 0.38 |
| Spinning | 0.43 |
| Knitting | 0.12 |
| Dyeing | 0.76 |
| Making and transport | 0.06 |
| Total | 1.75 |
Example values calculated with CarbonWear. Here almost half of the emissions come from dyeing: that is where precise supplier data and improvements pay off most. See a full sample report.
Primary data and average factors
Primary data is the real energy use measured by you or your suppliers. Average factors are industry or database values, useful when data is missing. The more primary data you have, the more the result describes your product rather than an average one. A good calculation states, line by line, which kind of data it used and where it came from.
What EU rules require
- ESPR, Regulation (EU) 2024/1781 on ecodesign: it introduces the Digital Product Passport. Textiles are among the first sectors covered; detailed requirements will come in specific acts.
- PEF, Recommendation (EU) 2021/2279: the EU method for the environmental footprint of products. For clothing, the detailed rules are in the PEFCR Apparel & Footwear.
- Directive (EU) 2024/825, applicable from 27 September 2026: it bans generic environmental claims (“green”, “eco”) that cannot be substantiated. Anyone communicating an environmental figure must be able to document it.
A calculation with traceable sources and data is the basis for answering customer requests and preparing for these obligations. It does not replace a full PEF study or third-party verification where those are required.
Common mistakes
- Using only industry averages when suppliers could provide real energy data.
- Entering a department’s yearly energy use without dividing it by the garments produced.
- Ignoring the country where processing happens.
- Hiding missing data instead of stating it.
- Presenting an estimate as if it were a certification.
Try it with one of your garments. The calculator is free and shows the source of every value.