Calculate CO2 footprint: Guide for companies

Why calculating the CO? footprint is vital today

Let’s be honest: the days when a sustainability report was just a nice extra in an annual report are over. Today, the ability to calculate your carbon footprint is no longer an optional marketing measure, but a crucial building block for long-term success. It’s no longer just about image, but about hard-hitting competitive advantages that can decide the future of your company.

Many decision-makers still see carbon accounting as an annoying obligation that primarily means costs and effort. However, the cleverest companies have long since turned the tables. They use the analysis of their emissions as a strategic tool. If you know exactly where the biggest emission drivers are lurking in your company, you can take targeted action, protect the climate and save a lot of money at the same time.

More than just a clear conscience: hard facts

Imagine that a detailed analysis shows you that a large part of your energy costs – and therefore also your emissions – come from outdated machines or inefficient logistics routes. This insight is pure gold. It gives you the opportunity to make investments that pay off twice over: through lower operating costs and a better carbon footprint.

But it’s about much more than cost savings. Regulatory requirements are becoming ever stricter. The Corporate Sustainability Reporting Directive (CSRD) requires more and more companies to report transparently on their sustainability performance. Those who create a solid database at an early stage not only avoid severe penalties, but also show themselves to be a reliable and forward-looking partner for investors and banks. Financial institutions increasingly see climate risks as tangible business risks and give preference to companies that have their emissions under control when granting loans.

The market rewards transparency and foresight

However, the pressure is not only coming from politics. Customers, especially younger generations, are actively asking for sustainable products and services. A credible carbon footprint is increasingly becoming a decisive purchasing argument. Companies that can communicate their progress openly build trust and secure the loyalty of a growing, environmentally conscious target group. An example from the furniture industry shows this impressively: a medium-sized manufacturer calculated its footprint and was then able to reduce emissions in its supply chain in a targeted manner. He communicated this proactively and won a major contract from a hotel chain for which sustainability was a key criterion in procurement.

This trend will only intensify. Greenhouse gas emissions in Germany fell again by 3.4% in 2024, clearly demonstrating the will for change in society as a whole. Companies that not only participate in this change, but actively shape it, will be among the winners. You can find out more about the latest emissions data and trends directly from the Federal Environment Agency.

To summarize: anyone who knows and calculates their carbon footprint today is investing directly in their own resilience. It is the basis for:

• Cost efficiency: finding and exploiting potential savings.
• Risk management: Be prepared for new laws and climate risks.
• Market opportunities: Gain new customers and strengthen your own brand.
• Access to capital: Better conditions with banks and greater attractiveness for investors.

Those who ignore this strategic lever risk being left behind in the coming years – not only socially, but above all economically.

Understanding Scope 1, 2 and 3 without headaches

When you hear about Scope 1, 2 and 3 for the first time, it probably sounds like complicated bureaucracy. But don’t worry, the concept is more logical and practical than it seems at first glance. Basically, it’s just a matter of sorting your emissions into three clear “pots” to keep an overview. Imagine you are tidying up a messy garage: you sort everything into boxes that you label “My stuff”, “Borrowed stuff” and “Stuff generated by my orders elsewhere”. This is exactly what we are now doing with your CO? emissions.

The three scopes in plain text

The division into the three scopes helps you to clearly define your areas of responsibility. It separates the emissions over which you have direct control from those that you only influence indirectly.

Scope 1: Direct emissions – your own chimney

Everything that is produced directly in your company through combustion processes ends up here. These are the emissions that you can literally see or feel. Think, for example, of:

• The gas or oil heating system that warms your offices and halls.
• The fuel consumption of your fleet, i.e. all cars, vans or trucks belonging to your company.
• emissions from industrial processes if you use chemical reactions in production.

A typical example: a medium-sized haulage company records the entire diesel consumption of its truck fleet under Scope 1, including the heating oil for the warehouse. The company has direct control over these emissions and can influence them directly through measures such as route optimization or conversion to e-vehicles.

Scope 2: Indirect emissions from energy – electricity from the socket

This area is also quite easy to grasp. This is about the emissions that are produced when generating the energy you buy. You don’t burn anything yourself, but your energy supplier does it for you. This includes

• Purchased electricity
• Purchased district heating or district cooling
• Purchased steam

If your office building is supplied with electricity from a coal-fired power plant, the resulting CO? emissions fall into your Scope 2. The big lever here is to switch to a green electricity tariff from 100% renewable energy. You can often reduce your Scope 2 emissions to zero with a single phone call.

This process, from collecting consumption data and applying the right factors to the final calculation, can be easily visualized.

The graphic illustrates the core process: without solid consumption data and the appropriate emission factors, it is not possible to calculate the carbon footprint accurately.

Scope 3: The giant in the value chain

This is where it gets exciting and often challenging, because Scope 3 includes all other indirect emissions that occur throughout your entire value chain. For many companies, these account for over 80 % of the total carbon footprint. They are more difficult to record, but this is where the greatest potential for effective climate protection lies.

Scope 3 is divided into 15 categories. But don’t panic, you don’t have to analyze them all. Concentrate on the ones that are most important for your business model.

The following table gives you a more detailed insight into how you can assign typical emission sources to the three scopes.

Scope categories at a glance: Correctly assigning emission sources
Detailed breakdown of the three scope categories with specific examples for different types of companies

Scope category	Scope description	Typical emission sources	Calculation approach
Scope 1	Direct emissions from sources that the company owns or controls.	Heating oil & natural gas for own buildings Diesel & gasoline for the company fleet Process emissions (e.g. chemical reactions)	Consumption data (e.g. liters of diesel, kWh of gas) x emission factor
Scope 2	Indirect emissions from the generation of purchased energy.	Purchased electricity Purchased district heating, cooling & steam	Consumption data (kWh electricity) x emission factor of the energy supplier
Scope 3	All other indirect emissions generated in the company’s value chain.	Purchased materials & services Transportation by third parties Business travel (flights, hotels) Use of products sold Waste disposal	Often more complex: expenditure-based (€) or activity-based (e.g. freight tonne-kilometers)

As the table shows, Scope 3 often requires a different approach. While Scope 1 and 2 are calculated directly using consumption data, Scope 3 sometimes requires estimates or expenditure-based data.

Here are some of the most important Scope 3 categories with examples:

• Purchased goods and services: The production of the raw materials and components you need for your products. A car manufacturer must take into account the emissions from the steel and aluminum production of its suppliers.
• Transportation and distribution: All logistics services that you do not carry out with your own vehicles. This includes deliveries from suppliers (upstream) and shipping to customers (downstream).
• Business trips: Flights, rail travel and hotel accommodation for your employees.
• Use of the products sold: The emissions generated when your products are used by the end customer. A manufacturer of gas boilers must take into account the gas consumption of the appliances over their entire service life.
• Waste disposal: The emissions generated during the disposal of operational waste.

The key to success is not to try to do everything at once. Start with the areas where you think you have the biggest emissions and for which you have the easiest access to data. If you would like to find out more about practical implementation and prioritization, you can find a useful guide to creating a carbon footprint for companies here.

Data collection that doesn’t end in chaos

Once we have categorized the scopes, it’s time to get down to business: data collection. This is where many projects come to a standstill. The good news first: the math to calculate the carbon footprint is surprisingly simple. The real trick is to get the numbers right without getting bogged down in a jumble of Excel spreadsheets, endless email chains and incomplete calculations. The goal is to build a clear process that gives you reliable data – without making your colleagues roll their eyes at every request.

Most of the information you need is already hidden somewhere in your company. You just need to know where to start looking. Think of it like a treasure hunt. Your business processes are the treasure map, and the treasures are consumption data such as kilowatt hours of electricity, liters of diesel or tons of steel purchased.

Where the data really lies: a departmental check-up

Instead of blindly chasing emails through the company, we prefer to take a strategic approach. Each department holds a different part of the data treasure trove. Good preparation and clear announcements are the key to getting the right people on board and keeping them motivated.

Here is a tried and tested breakdown to help you get started:

• Accounting & Controlling: This is your goldmine for Scope 1, 2 and a large part of Scope 3. All invoices for energy (electricity, gas, district heating), fuel (fuel card statements) and purchased goods and services are stored here. Ask specifically for annual statements from energy suppliers and the total expenditure for certain material groups.
• Purchasing & Procurement: This department knows the stories behind the invoices. It can provide you with exact quantities and specifications of the materials purchased. Instead of just using the euro amount for “office supplies”, Purchasing can tell you how many packets of paper (and what type) were actually purchased. This makes your calculation many times more accurate.
• Facility Management & Building Services: Your colleagues here are the custodians of Scope 1 and Scope 2 data. They often have direct access to the meter readings for heating, electricity and water. They also know which refrigerants are in the air conditioning systems – an often overlooked but very potent source of emissions.
• HR department & travel expense accounting: The HR department is the first port of call for the Scope 3 categories “Business travel” and “Employee commuting”. Here you can obtain aggregated data on air miles, rail travel and hotel stays. HR can also help with the coordination of employee commuting surveys.
• Logistics & Fleet Management: If you have your own fleet of vehicles, this department provides the crucial data for Scope 1, including kilometers driven, exact fuel consumption per vehicle type and information on maintenance.

Systematic instead of paperwork: your data cockpit

To avoid losing the overview, you should use a central structure for recording from the outset. A simple but well-structured Excel spreadsheet or a shared online document can work wonders here.

Best practice for data collection

Data point	Scope assignment	Department	Data source	Status	Comments
Power consumption	Scope 2	Accounting/Facility	Annual energy supplier bill	Received	Check the proportion of green electricity
Natural gas consumption	Scope 1	Accounting/Facility	Annual energy supplier bill	Requested	Extra meter reading
Diesel consumption fleet	Scope 1	Fleet management	Fuel card billing	Received	Breakdown per vehicle type
Business travel (flight)	Scope 3	Travel expenses/HR	Billing system	In progress	Only flown km, not €
Purchased paper	Scope 3	Purchasing	Supplier invoices	Open	Recycled vs. virgin fiber

This structured approach not only helps you, but also your colleagues. Everyone can see at a glance what is needed and why.

Data gaps are often one of the biggest hurdles. What if exact consumption data simply cannot be found for an area? Don’t panic. It is perfectly legitimate and accepted to work with well-founded estimates. For example, if you don’t know the exact emissions of your waste disposal, you can take the costs from your accounts and apply an expenditure-based emissions factor. The only important thing is that you document such assumptions transparently.

Data collection is more than just a technical exercise; it gives us a fascinating insight into the real-world impact of our consumption. To put it all into context: The average carbon footprint per person in Germany in 2024 was around 10.3 tons of CO? equivalents. This figure, which is based on our total consumption, shows how deeply our daily decisions are linked to global emissions. You can find more insights on this topic under consumption-based emissions on Statista.com. Your corporate footprint is part of this overall picture, and accurate data collection is the first step to actively shaping it.

Mastering emission factors without studying math

As soon as you have your consumption data together, the exciting part comes: converting these figures into tangible CO? values. This is where the emission factors come into play. And don’t worry, you don’t need a degree in mathematics to do this. An emission factor is basically just a conversion value that indicates how many kilograms of CO? equivalents (CO?e) are produced per unit consumed – for example, per liter of diesel or per kilowatt hour of electricity.

The formula itself is very simple: consumption volume × emission factor = CO?e emissions. The real challenge lies in finding the correct and, above all, most up-to-date factor for the respective activity and region. This is because using an outdated or inappropriate factor can ruin the accuracy of your entire balance sheet.

Finding the right factors: Your trusted sources

Fortunately, you don’t have to invent these values yourself or read them on the coffee grounds. There are established and scientifically sound databases that you can easily access. For companies in Germany, the most important point of contact is the Federal Environment Agency (UBA). The UBA regularly publishes updated emission factors for Germany, which are regarded as the national standard.

A practical example: Your company has calculated an electricity consumption of 50,000 kWh. Instead of using a generic European value, you use the specific factor for the German electricity mix from the UBA. This takes into account the exact proportion of coal, gas and renewable energies in the German grid and is therefore much more precise. Current data and further information can be found directly from the experts at the Federal Environment Agency.

In addition to the UBA, there are other recognized international databases such as DEFRA (for the UK) or Ecoinvent, which are often necessary for more complex Scope 3 calculations or international supply chains. Many CO? software solutions already have these databases integrated, which simplifies the work considerably.

Pitfalls and tricky cases in practice

It gets really interesting when we go beyond simple consumption such as electricity and gas. For example, how do you calculate the emissions of a flight or the production of a purchased product?

• Business trips: Here, it is not enough just to know the kilometers flown. A serious emissions factor also takes into account the flight altitude, as contrails have a greater impact on the climate at high altitudes, and the aircraft’s load factor. Travel data providers or specialized calculators often provide more detailed factors here.
• Purchased goods (Scope 3): This is often the trickiest category. There are two common approaches here. The more accurate, but also more complex way, is to use activity-based factors. For example, if you buy 10 tons of recycled paper, you use a factor that indicates the emissions per kilogram of paper. Studies show that the production of 1 kg of recycled paper causes around 0.7 kg of CO?e, compared to 1.2 kg of CO?e for virgin fiber paper.
• The more pragmatic approach is expenditure-based. If you don’t know the exact amount, simply take the expenditure (e.g. €5,000 for office supplies) and multiply it by a factor that gives kg CO?e per euro for that product category. Although this approach is less accurate, it is a recognized way to close data gaps.

The following table gives you an overview of some typical emission factors so that you can get a feel for the order of magnitude.

Important emission factors for German companies
Overview of the most common emission factors with current values and sources for precise CO2 calculations

Emission source	Unit	Emission factor (kg CO2e)	Data source	Update cycles
Electricity (German mix)	kWh	~ 0,35 – 0,40	Federal Environment Agency (UBA)	Annually
Natural gas	kWh	~ 0,202	UBA / GEMIS	Annually
Heating oil	Liter	~ 2,66	UBA / GEMIS	Annually
Diesel	Liter	~ 2,65	UBA / GEMIS	Annually
Air travel (domestic)	passenger kilometer	~ 0,25 – 0,29	UBA / atmosfair	Annual/continuous
Paper (virgin fiber)	kg	~ 1,2	Ecoinvent / studies	Every 2-3 years

It is clear from this table that the choice of source and the timeliness of the data are crucial. Factors for the energy mix or fuels are adjusted annually, while product-related data is often updated in longer cycles.

Transparency is very important: always document which emission factors and which data source you have used to calculate your carbon footprint. This not only creates trust, but also makes your balance sheet comprehensible and credible.

CO2 tools and software that really help

Once you have collected your data and found the appropriate emission factors, the crucial part comes: the actual calculations. Do you plunge into Excel spreadsheets manually or do you prefer to rely on specialized software? There is a wide range of tools that promise to calculate your carbon footprint, from simple online calculators to comprehensive software packages for corporations. But which solution really suits you and when does it make sense to invest?

When free calculators are sufficient (and when they are not)

Free tools are a good starting point for getting an initial feel for the dimensions of your carbon footprint. An excellent and trustworthy address here is the Federal Environment Agency’s CO? calculator, which is particularly suitable for private individuals or very small businesses. It provides a solid basis with recognized emission factors. However, these simple calculators quickly reach their limits as soon as things become more complex – for example, if you want to map detailed Scope 3 categories, need an auditable balance sheet or want to set up ongoing monitoring.

The next step for many is manual calculation in Excel. Although this offers maximum flexibility, it is also prone to errors. A typing error in a formula can quickly occur, the emission factors have to be laboriously updated by hand and teamwork quickly becomes chaotic. Our experience shows: What initially appears to be a favorable solution often develops into a time waster as soon as more than one person is involved or the balance sheet has to be recreated annually.

The leap to professional software: a worthwhile investment

Professional CO? management software relieves you of many of these tedious tasks. It accesses up-to-date emission factor databases, guides you through the data collection process in a structured manner, ensures complete documentation and creates meaningful reports at the touch of a button. This not only saves you a lot of time, but also significantly increases the credibility of your carbon footprint.

Before you decide on a provider, you should take a close look. A good tool is characterized by the following features:

• Certification: The calculation methodology should comply with recognized standards such as the GHG Protocol.
• Scalability: The software should be able to grow with your company – from the first balance sheet to comprehensive sustainability management.
• Interfaces: Connections to existing systems, for example your accounting software, can make data collection much easier.

The above screenshot of the Federal Environment Agency’s website shows an important point of contact for validated information and recognized environmental management systems such as EMAS. Such official sources are worth their weight in gold for checking the quality and methodology of software providers.

The results of your calculations are more than just figures for a report – they are the basis for your strategic decisions. The results can be incorporated directly into your sustainability report, which is becoming increasingly important in communication with investors, customers and partners.

This focus on validated data and strategic reduction is part of a positive trend. CO? emissions in Germany have fallen considerably since 1990, a strong sign of progress in climate protection. By 2023, emissions had fallen to around 673 million tons, which corresponds to a reduction of 46%. With precise measurements and targeted measures, your company can also become part of this success story. You can read more about this impressive development at Statista.

Avoid typical mistakes and avoid pitfalls

The journey to the finished carbon footprint is paved with a few pitfalls that many have stumbled over before you. This is good news, because you can learn from these experiences and avoid the most common mistakes from the outset. When you calculate your **CO? footprint**, it’s not just about adding up numbers, but also about working methodically and accurately. One small mistake can call into question the validity of your entire balance sheet.

One of the most classic mistakes that we repeatedly encounter in practice is double counting. Imagine your logistics department balances the emissions of your own truck fleet (Scope 1), while the purchasing department simultaneously balances the emissions for “purchased transport services” (Scope 3) – and inadvertently includes the same journeys. Such overlaps massively distort the result. Clear demarcation and open communication between the departments are crucial here.

From false assumptions and inaccurate data

Another stumbling block is the incorrect assignment to scopes. This happens particularly often with leased vehicles. Many companies intuitively book these under Scope 1, just like their own vehicle fleet. According to the GHG Protocol, however, emissions from leased vehicles are usually assigned to Scope 3 category 8 (“upstream leased goods”), as the vehicle is not owned by the company. Such details are crucial for a standard-compliant balance sheet.

Unrealistic estimates are just as dangerous. Sometimes it is tempting to make generous estimates in the event of data gaps in order to make rapid progress. But caution is advised here. An estimate should always be the last option and should be conservative.

Practical tip on data quality:

• When is an estimate okay? For smaller emission sources where the effort required for exact data would be disproportionate (e.g. exact water consumption in the office). Always document your assumptions transparently.
• When is exact data mandatory? For all major sources of emissions that make up a significant part of your footprint. Accurate accounting is essential for the electricity consumption or fuel of your main logistics route.

The warning signals that should make you sit up and take notice

Look out for inconsistencies in your data. For example, if your accounting department reports high expenditure on paper, but the emissions in your balance sheet are negligible, something is wrong. A 100-page DIN A4 manual made from recycled paper already generates around 0.44 kg of CO?e, just for materials and printing. With a print run of 10,000 copies, this quickly adds up. If such items are overlooked, a relevant part of your Scope 3 footprint is missing.

Treat your CO? balance sheet like your financial accounts: with care, clear rules and a dual control principle. An internal or external review before publication is always a good idea. This will ensure that your figures are not only correct, but also credible – the most important currency in sustainability management. After all, the balance sheet is not an end in itself, but the basis for effective reduction strategies. If you are looking for inspiration for concrete next steps, you will find clear examples of how you can put your findings into practice in our article on ESG measures.

Your action plan for successful carbon accounting

Okay, now you know the basics of scopes, data and emission factors. Time to turn it all into a solid roadmap. Don’t worry, calculating your carbon footprint doesn’t have to be an insurmountable project if you approach it wisely. It’s all about putting the knowledge into practice – with a clear plan, realistic goals and a focus on quick, motivating results.

From stocktaking to climate strategy

Your path to carbon footprinting doesn’t start with a complicated analysis of all Scope 3 emissions. Instead, start simple: with a solid inventory of the things you can control directly. These are your Scope 1 and Scope 2 emissions. Simply collect the annual bills for electricity, gas and heating oil as well as the fuel receipts for your vehicle fleet. With this data, which is usually quickly to hand, you can already calculate around 80% of your directly controllable footprint. A great start to see your first successes.

Once this foundation is in place, you can gradually expand your view to Scope 3. Start with the categories that are most important to your business and where data collection is easiest. These are often business travel, waste disposal or purchased logistics services. This first, perhaps still incomplete balance sheet is more than just a figure for a report – it is a strategic tool for internal decision-making. Where is the greatest potential for savings? Which investment in greater efficiency will pay off the quickest?

Your timetable for the first 30 days

A clear timetable helps to get things moving and avoid putting the issue on the back burner. Celebrate even the small successes and make progress transparent within the team.

• Week 1: Team & kick-off. Appoint a responsible person and bring together the most important departments such as accounting, purchasing and facility management. Define together what you want to achieve and who will take on which tasks.
• Week 2-3: Data sprint. Now it’s time to roll up your sleeves. Concentrate fully on obtaining the consumption data for Scope 1 and 2 from the last financial year. At the same time, you can request the first aggregated data for business travel and waste.
• Week 4: First calculation & analysis. Compile all the data in a tool or simple spreadsheet and calculate the first draft of your footprint. Identify the top 3 sources of emissions in your company and present them to the team.

This initial carbon footprint is the perfect starting point for an effective climate strategy because it shows you where your actions will make the biggest difference. To underpin your reduction targets with visible and measurable actions, Click A Tree offers simple solutions. Integrate sustainability directly into your processes and make your commitment tangible for customers and partners.