- Life cycle assessment (LCA) evaluates a product's environmental impacts across its whole life, framed by the ISO 14040 and 14044 standards.
- The product carbon footprint is its climate component, expressed in CO2e, under the ISO 14067 standard.
- The calculation follows four steps (goal, inventory, impacts, interpretation) and multiplies activity data by emission factors, step by step.
- A simplified LCA is enough to guide decisions; a full LCA, often subject to critical review, is required for external communication or a regulated claim.
What is an LCA (life cycle assessment)?
An LCA is a method that evaluates the environmental impacts of a product or a service across its entire life cycle: raw material extraction, manufacturing, transport, use, end of life. It is called cradle to grave when it covers this whole cycle, and cradle to gate when it stops at the factory gate. You will also come across the term cradle to cradle, which refers to a circular logic where a product's end of life feeds a new cycle.
An LCA is multicriteria: it does not measure only carbon, but also water consumption, resource depletion, acidification, and other impacts. It is framed by the international standards ISO 14040 and ISO 14044, which set out its principles and requirements.
What is the difference between LCA and product carbon footprint?
The product carbon footprint is the climate component of an LCA. Where the LCA covers several environmental impacts, the product carbon footprint focuses on a single indicator: the product's greenhouse gas emissions, expressed in CO2e over its life cycle. It follows the ISO 14067 standard, which builds on the principles of LCA (ISO 14040 and 14044).
In plain terms: every product carbon footprint rests on an LCA logic, but a full LCA goes beyond carbon alone. You speak of a product carbon footprint when the question asked is a climate one; of an LCA when you want a broad environmental view, for example for ecodesign.
What are the steps of an LCA?
The ISO 14040 standard defines an iterative process in four steps:
- Goal and scope definition. What the LCA is for, which product, which boundaries (cradle to grave or to gate), which reference unit.
- Life cycle inventory. You list all incoming and outgoing flows: materials, energy, transport, waste, emissions, at each step.
- Impact assessment. You translate this inventory into environmental impacts, including climate change in CO2e.
- Interpretation. You analyze the results, identify the main contributors and the improvement levers.
The iterative nature matters: you refine the scope and the data as the study goes on, as the biggest contributors appear.
How do you calculate a product's carbon footprint?
On the same principle as any carbon calculation: you multiply activity data by emission factors, but this time step by step across the product's life cycle. For each phase (materials, manufacturing, transport, use, end of life), you collect the relevant quantities and apply the corresponding factor, then add them up.
The factors come from the same databases as for a company footprint: the ADEME Base Empreinte, complemented for products by life cycle assessment databases such as Agribalyse (food) or Ecoinvent (international). The difficulty is not the calculation, but collecting the data at each step and choosing consistent boundaries.
When should you settle for a simplified LCA?
When the goal is to guide decisions, not to communicate an official figure. A simplified (or screening) LCA uses less data and gives a quick view of the contributors that matter: it is enough to compare two design options or prioritize ecodesign actions. A full LCA, heavier and often subject to critical review, becomes necessary when the result is intended for external communication, an environmental product declaration or a regulated claim. The gap in effort is real: from our experience, a full LCA often represents several months of work for a single product, on the order of six months with data collection and critical review, whereas a simplified LCA is carried out in a fraction of that time. As with a company footprint, you start simple and refine.
Link product impact to your carbon strategy with Ditto
A product's footprint does not live in isolation: it feeds your scope 3, your customer responses and your ecodesign arguments. Ditto centralizes your carbon data at the organization level, structures your scope 3 and helps you reuse your product data where it counts, in your ratings and your responses to clients. For a detailed, multicriteria product LCA, specialized tools and experts are often still needed; Ditto makes the link with your overall carbon approach. And for a first product calculation, a platform saves time, but a clear boundary and the Base Empreinte factors already give you a reliable base to work from.
Link your product data to your carbon footprint
A Ditto expert reviews how to make the most of your products' impact in your scope 3 and your ratings.
LCA and product carbon footprint: key takeaways
| Item | Summary |
|---|---|
| LCA | Environmental impacts of a product across its whole life cycle, multicriteria (ISO 14040 / 14044) |
| Product carbon footprint | Climate component of the LCA, in CO2e (ISO 14067) |
| Boundary | Cradle to grave or cradle to gate |
| Steps | Goal and scope, inventory, impact assessment, interpretation |
| Calculation | Activity data × emission factor, step by step |
| Company link | Feeds the scope 3 of the carbon footprint and ecodesign |
Frequently asked questions
What is a product LCA?
A product's life cycle assessment evaluates its environmental impacts across its whole life, from material extraction to end of life. It is multicriteria (climate, water, resources, and so on) and framed by the ISO 14040 and 14044 standards.
What is the difference between LCA and product carbon footprint?
The LCA measures several environmental impacts; the product carbon footprint keeps only one, climate, expressed in CO2e over the life cycle, under the ISO 14067 standard. The product carbon footprint is the climate component of an LCA.
How do you calculate a product's carbon footprint?
By multiplying, for each life cycle step (materials, manufacturing, transport, use, end of life), the activity data by the corresponding emission factors, then adding them up. The factors come from the ADEME Base Empreinte and from LCA databases such as Agribalyse or Ecoinvent.
Full LCA or simplified LCA: which one to choose?
A simplified LCA is enough to guide internal decisions or compare ecodesign options. A full LCA, often subject to critical review, is required when the result serves external communication, an environmental declaration or a regulated claim.
