The 3 different methods to calculating your firm’s carbon footprint

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 A carbon footprint assessment is an analysis that can be carried out by any firm to estimate its greenhouse gas (GHG) emissions and to find solutions to reduce them. This assessment is based on a precise methodology.

A comprehensive carbon footprint is made up of three scopes (direct emissions, energy consumption, and indirect emissions). Check out our dedicated article on this subject to find out more! For a carbon footprint calculation to be representative, it must be exhaustive

How should you carry out your firm’s carbon footprint assessment? Should you go for a consulting firm, a SaaS (software as a service) or do it yourself? Read along to find out all about the different methods available

The 3 methods to assessing your carbon footprint

 If a carbon footprint were a book, there could be different processes for producing it:

  • Assembling the pages by hand. This is the consultancy approach, which ensures a quality carbon footprint. However, this method is usually expensive and often takes several months.

  • Industrialising the publication without proofreading. This is the SaaS (software as a service) approach, online and fully automated. Ultimately, it has the advantage of being fast and cheaper, although it is also less reliable.

  • The manuscript. This is a stand-alone approach, without consulting nor SaaS, where a firm trains its employees to carry out its carbon footprint in-house.

  • Industrialising the printing with content review

    . This is the approach developed by Carbometrix, combining the best of both automation and consulting, saving time for your team! 

Learn all about these different methods with their respective benefits and drawbacks. You’ll also get to know all about the approach developed by Carbometrix.

First method: calling upon a consultancy firm

The first option for drawing up a carbon footprint is to call upon the services of a specialist consultancy firm. The latter can draw up a complete carbon assessment document, taking into account scopes 1 and 2, and even 3. They may potentially help you formulate concrete proposals in order to reduce your activities’ environmental footprint.


  • Support. A consultant gives and explains the often complex steps and calculation methods of a carbon assessment procedure. Above all, they will help you understand the data collection process, which is often very precise and exhaustive.

  • Transformation. A carbon assessment is both a report detailing the sources of your carbon footprint and an action plan proposing concrete solutions to reduce your emissions. The role of an expert consultant is also to help you manage the change and the associated projects after calculating the balance sheet. This is done in the aim of helping your firm modify its practices.

  • Attention to detail. The advantage of using an expert compared to other methods is that they will provide a detailed report and that the duration of the service will allow all the actors involved in the collection to become aware of the situation.  


  • Time. The collection and processing of various data, followed by the development of solutions to reduce the firm’s polluting activities require considerable time. It is often necessary to wait several weeks, or even several months, before the full carbon footprint is available.

  • Price. Using a consultancy firm is undoubtedly the most expensive method of establishing a carbon balance sheet. You should expect to spend several thousand euros.

  • Access to system data. An expert will often need access to all the data relevant to your business operation. It may take time to collect this data.

  • Lack of overall vision. A very exhaustive methodology can lead to a set of recommendations that may be difficult to prioritise, mixing actions that are sometimes anecdotal with those that have a strong impact. It may therefore be difficult to focus on the most urgent actions to truly decarbonise one’s value chain. This includes third party activities such as suppliers, which only a scope 3 carbon footprint assessment can account for.   

Second method: using a SaaS 

SaaS (software as a service) is a licensing model for delivering software applications over the Internet.

In this specific case, establishing a firm’s carbon footprint with a SaaS uses its software and computing systems to provide the data needed to establish its carbon balance.  


  • Ease of use. Data collection is automated, which makes it easier and faster to collect data than opting for a consultancy firm’s services.

  • Speed. These platforms are usually accessible online and their calculation method is fully automated, meaning that you can order and receive your carbon footprint balance within a short timeframe.

  • Price. A carbon footprint assessment carried out by a SaaS costs around 10 times less than calling upon an expert. 


  • It is not a reliable assessment. Many automated calculators do not take into account scope 3 carbon emissions. They are indeed the most difficult to account for, but they are also the most important! A SaaS-automated sheet is therefore often incomplete.

  • There is no objectivity from an external party. A carbon footprint assessment produced by a SaaS is not subject to an expert’s analysis, better positioned to assess emission sources to make adequate recommendations adapted to the firm’s activities.

  • There is no adaptation of the platform. A SaaS is static and does not adapt to the reality of a firm’s activities. Indeed, the different fields’ relevance is not assessed and all of them appear equally on the balance sheet, although they may not all be applicable or significant to the concerned firm.

  • Finally, these platforms often rely on accounting or financial data, which only provide a very rough monetary insight. 

  • Such an analysis is quite intrusive of a firm’s computing software and activities.  

A third method: carrying out your carbon assessment independently 

You can also choose not to call upon any external service provider and carry out your carbon footprint assessment yourself. As the carbon assessment methodology established by the French Agency for Ecological Transition (ADEME) is complex, training one or more of your employees for this specific task is needed.

The French Carbon Training Institute (or Institut de Formation Carbone) offers certified training courses (of approximately 2 days, either in person or online) for a fee varying from €1150 to €1250. Your trainee will undertake a carbon footprint calculation on Excel using the specific tool developed by the French Association Bilan Carbone (ABC).


  • The training of in-house experts. By these means, your firm integrates a new skill: carbon assessing. The recommendations made will be all the more effective and appropriate if they have been developed by employees who are familiar with the way the firm operates.

  • Total confidentiality. By training your own experts, you ensure that no third-party gains access to information related to your firm’s operation. 


  • The lack of reliability. A carbon footprint assessment encloses a few difficulties that may remain difficult to address, such as the inclusion of scope 3 emissions factors. The risk is that this type of in-house assessment lacks accuracy.

  • Significant training time. An e-learning training requires at least 16 hours in an employee’s schedule, and even more if you choose to go for face-to-face training.

  • Gaps in recommendations. Despite their training, in-house experts do not acquire the same level of skills and knowledge as professional consultants. The conclusions and proposed solutions will most certainly be less sophisticated than those of specialists.

The Carbometrix method: combining consulting and SaaS

Combining the skills of experts with the ease of use of a SaaS: this is the solution offered by Carbometrix.

Carbometrix works like a SaaS in the sense that:

  • It is a platform that allows collaborative work on data;

  • It fosters the development of proprietary calculators for fast report generation;

  • It relies on a big data approach allowing automatic sectoral ranking;

  • It offers a much lower price than what consulting firms offer.

In addition to this, Carbometrix holds a consulting aspect:

  • Carbometrix offers human support to help you understand the questionnaire, data collection and completion and remains at your disposal to provide explanations and answers to any questions you may have.

  • If produced by an automated calculator, the carbon footprint proposed by Carbometrix is

     systematically checked and analysed by an expert.

  • The carbon footprint is presented in person so that the main information points can be extensively explained if necessary and recommendations for action detailed.

  • Carbometrix is particularly keen to provide customised recommendations for action 

    (such as the provision of decarbonisation paths), going beyond the calculation of a firm’s carbon footprint.

Conclusion: the different ways of assessing your carbon footprint

 The most suitable carbon footprint assessment method depends upon your objective, your resources and your maturity in regards to carbon performance. 

Carbometrix’s assessment method combines the ease of use of a SaaS solution, the reliability of proprietary calculators based on industry data, formulas that integrate the most relevant emission factors for each emission item, company or sector, as well as carbon engineers who verify the data produced and establish suitable recommendations.

Are you convinced by our carbon footprinting assessment method? Get in touch with us now!

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