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The 5 Best Free Carbon Footprint Calculators in 2024

Article Overview

There’s a new high bar for transparency, traceability, and consistency in climate reporting. Regulations emerging around the world demand audit-grade GHG emissions data — and investors, customers, and other stakeholders increasingly want to see detailed information about how businesses measure their climate impact and risk.  

In this atmosphere, tracking information on spreadsheets is no longer enough. To meet climbing expectations for data quality, businesses need technology designed specifically for carbon accounting. Software that automates emissions calculations can eliminate errors and facilitate communication with stakeholders — setting organizations up for stronger climate disclosures and enhanced credibility. 

Below, we’ll give an overview of the features you should look for when selecting your carbon footprint software, and the leading free tools available today. 

What is carbon footprint software?

Carbon footprint software automates emissions calculations.

Carbon footprint software refers to computer programs and applications that measure, analyze, and help reduce the carbon footprint of individuals, organizations, products, or services. Historically, many companies have relied on spreadsheets to track their emissions, which can lead to mistakes and impede real-time data-sharing by different teams. By automating calculations, carbon footprint software can save significant staff time and improve the accuracy of climate disclosures. 

Even if your company is not yet required to disclose emissions to a regulatory body, investing in carbon footprint software enables you to easily share your data with investors and customers, which sends a positive market signal. One recent study showed that 60% of investors would pay a premium for companies that demonstrate ESG maturity — and quality carbon data is a strong indicator of that maturity.  

What features should you look for in free carbon footprint calculators?

Transparency, traceability, and comprehensive emissions data are key.

Not all carbon software is created equal. The standards for data quality continue to climb, and you need to ensure your platform of choice can meet them. Here are the essential features you’ll want to look for as you select your carbon footprint software: 

1. Robust Coverage for Scopes 1, 2, and 3

New reporting mandates, combined with an upward trend in net-zero commitments, mean that many companies now have to calculate their scope 3 emissions in addition to scopes 1 and 2. This also means moving away from spend- and revenue-based estimates to using actual activity data, which is often a challenge for value chain emissions. Software can be particularly helpful here — especially if it facilitates supplier engagement and allows users to plug in their actual activity data using a consistent calculation methodology.  

2. Ability to Collect Granular Scope 3 Data

Reliable data is the bedrock of your credibility. When it comes to calculating scope 3 emissions, spend-based estimates provide an adequate starting point, but ultimately, to build trust with stakeholders and make meaningful reductions, you’ll need much more granular information. This requires engaging with suppliers and portfolio companies to collect their primary scope 1 and 2 emissions data in a standardized and scalable way. Ideally, you will use actual emissions data submitted by suppliers in your scope 3 calculations, rather than estimating emissions based on spend or averages — and your software should support this. 

3. Streamlined User Interface

Let’s face it: Calculating carbon emissions is hard enough without having to navigate confusing tools. Your platform should appeal to users with a wide range of experience, so it can be used by different teams within your organization, as well as suppliers and portfolio companies around the world. Stakeholders with no prior carbon accounting experience should quickly be able to enter data and start calculating their carbon footprint. 

4. Data Transparency and Traceability 

As the regulatory environment evolves and stakeholder pressure rises, you need to be ready to show your work. Climate disclosure mandates from Europe, the US SEC, and California will require organizations to provide varying levels of assurance over their emissions data. Your carbon footprint platform should support audit-grade disclosures by ensuring data is traceable and transparent— so you can report your climate data with confidence. 

5. Support for Companies with Complex Organizational Structures

Many businesses operate in more than one country and will not only have to meet different disclosure mandates by region. Your carbon accounting software should reflect the unique structure of your business, and allow you to attribute emissions by region, business unit, and more. 

6. Ability to Share Emissions Data with Stakeholders

The whole point of carbon disclosure is to communicate with stakeholders — whether they are investors, customers, or regulators. A solid carbon footprint platform will make information-sharing easy and ensure everyone is working with the same reliable set of data. It should provide transparency into calculations and consistency in how emissions data is collected and measured, regardless of whether it comes from business operations, suppliers, or companies in an investment portfolio. 

The 5 best free carbon footprint calculators in 2024

*Based on Persefoni’s assessment of the carbon technology reporting landscape today. 

While carbon accounting can be daunting, several free tools are now available to help with the process. Your regulatory reporting requirements and stakeholder needs will help determine which carbon footprint software is right for you. 

Here is a roundup of five leading free carbon software platforms, based on Persefoni’s assessment of the carbon technology reporting landscape today: 

Persefoni Pro

Persefoni Pro is a free, self-guided platform for organizations of any size — from startups to Fortune 500 companies. Several features set this tool apart. First, it doesn’t require extensive carbon accounting experience. Its user-friendly interface taps into generative AI to provide in-platform support and expertise — cutting down on frustration and making carbon accounting approachable for a wide range of teams. 

Persefoni Pro is specifically designed to prepare companies for regulatory disclosure and auditing. To that end, it enables users to calculate a robust carbon footprint based on actual activity data (rather than less accurate revenue or spend-based averages) and offers full transparency into the calculation methodology. Another key innovation is Persefoni’s data exchange, which enables different users to readily share emissions calculations with each other within the same platform — ensuring footprints are measured using the same consistent framework. Finally, while many tools only support single-country operations, Persefoni Pro can handle the complexity of companies operating internationally. 

Persefoni Pro is a good choice if you’re a business of any size (especially those with complex or multi-country operations) looking for a free, user-friendly tool that ensures audit-grade data, facilitates supplier engagement, and helps you disclose to stakeholders and prepare for future regulatory reporting. 

Get started free with Pro today.

Climate Neutral Business Emissions Evaluator

The Climate Neutral Business Emissions Evaluator (BEE) was designed by The Climate Change Project, a nonprofit that offers carbon-neutral certification for companies. The BEE calculator helps organizations calculate their annual emissions as they work toward verification.

It covers all three scopes, using simple financial data for estimates. It provides users with emissions visualizations to help pinpoint the areas with the greatest opportunities for change. 

The Business Emissions Evaluator can support organizations with operations in multiple countries. Drawing from a deep library of publicly-funded emissions factors, the Business Emissions Evaluator captures the depth and range of products you really buy in your supply chain and operations. This is a good tool for you if you’re looking for a fast, free emissions estimate with the goal of earning carbon-neutral certification. 

Carbon Trust SME Carbon Footprint Calculator

The Carbon Trust was founded by the British government to help drive decarbonization for businesses, governments, and financial institutions. It supports organizations around the world in reaching net-zero goals — from target-setting to policy advice. 

The Carbon Trust’s footprint calculator is designed to help small and medium businesses in the United Kingdom measure direct emissions from their fuel consumption and processes (scope 1) and indirect emissions from purchased energy (scope 2). After users enter their data, the calculator provides a baseline emissions estimate, which can be used as a starting point for developing a strategy and earning verification from the organization. 

The Carbon Trust SME Carbon Footprint Calculator is a good tool for you if you’re a small or medium business looking to measure your scope 1 and 2 emissions and get help developing a net-zero strategy.

TerraPass Carbon Footprint Calculator

The TerraPass calculator offers emissions estimates for three different categories: businesses, individuals, and events. In calculating a business footprint, TerraPass considers a variety of factors, such as energy consumption, transportation, waste generation, and lifestyle choices. 

TerraPass offers a straightforward user experience: You’re asked to fill out an online questionnaire about your energy consumption and other details and are able to quickly see an initial emissions estimate. After submitting your information, you’ll receive an email from TerraPass with a final report on your footprint. As a next step, the company enables you to purchase its verified carbon credits to offset your emissions. 

Terrapass is a good choice if you are looking to calculate your footprint in order to make a decision about buying carbon credits to offset your business, lifestyle, or a major event like a wedding or a conference. 


Normative’s Business Carbon Calculator is geared towards helping small businesses calculate their carbon footprints. 

It provides an exportable summary report of emissions by scope, along with the ability to view industry benchmarks. Like Persefoni Pro, it features a streamlined interface, enabling users with varying levels of experience to engage with it. 

The Normative platform offers comprehensive reporting for all three scopes, using a hybrid of spend-based and activity-based calculations for scope 3. After using the carbon calculator, you can connect directly with Normative’s climate strategy team for help designing sustainable business growth plans. 

Normative is a good tool if you’re a small business operating in a single market and looking for a comprehensive emissions profile. 

Reliable climate data builds trust and credibility

Carbon footprint calculators are a foundational stepping stone.

The world is moving rapidly towards comprehensive, regulated climate disclosure — and nearly every company will feel the pressure to adapt. In the face of climbing expectations from regulators and stakeholders, the ability to share transparent, traceable, and reliable emissions data builds credibility and trust. 

Selecting the right carbon footprint calculator is crucial. Companies can get started by trying one of several free platforms available today. They should look for software that uses granular activity-based data and offers comprehensive calculations and a streamlined interface that’s accessible to teams with varying levels of experience. With the right tool in hand, carbon accounting can become less daunting, allowing you to focus time and resources on meeting your climate goals and staying competitive in a rapidly changing marketplace. 

Learn more about how Persefoni Pro’s free carbon platform can streamline carbon measurement for your company. 


What level of technical expertise is required to use free carbon footprint software effectively?

It depends on which tool you select. Several platforms are designed specifically to make carbon accounting approachable for users with little to no experience. For example, Persefoni Pro uses generative AI to support and educate teams who are new to carbon accounting. Because of this in-platform support, different functions within an organization can work independently to enter data and generate comprehensive emissions profiles. Users can access the Persefoni Knowledge Base, Persefoni Academy, and Persefoni Copilot (an embedded GPT-style interface) for self-service support throughout the onboarding process. A user-friendly interface also helps engage external parties. Businesses can share Persefoni Pro with suppliers as a way of gathering granular value chain data, while investors can use it to collect information from their portfolio companies. 

What types of data are needed to use free carbon footprint software effectively?

Data requirements will vary depending on the software, but they typically include energy consumption, transportation habits, waste generation, and other relevant activities that contribute to your carbon emissions. Some tools may also integrate data from industry benchmarks or public databases. The most comprehensive footprint calculators will build emissions profiles as much as possible based on actual activity rather than industry averages and spend-based estimates.

Are there any regulatory requirements or standards that free carbon footprint software should adhere to?

Some carbon footprint software aligns with international standards such as ISO 14064 or the GHG Protocol. While adherence to specific standards is not mandatory for free tools, compatibility with recognized frameworks enhances the credibility and comparability of results and helps prepare companies for regulatory reporting through the EU, the SEC, California, or other jurisdictions.

Are there limitations on the size or scale of organizations that can effectively use free carbon footprint software?

Some free carbon footprint calculators are designed specifically for smaller businesses or companies that operate in a single country. Others, like Persefoni Pro, are free and available to companies of any size, including those with operations in multiple countries and jurisdictions. These flexible tools enable smaller suppliers from around the world to enter their emissions data using the same consistent methodology as their larger customers — facilitating high-quality scope 3 calculations and transparent communication. 

Are there limitations to using free carbon footprint software compared to paid versions?

Free carbon footprint software can have limitations in terms of advanced features, support, and customization options compared to paid versions. When selecting a platform, users should consider whether the functionalities offered by free software will adequately meet their specific needs. 

Large companies subject to climate disclosure regulations may start their journey on a free tier like Persefoni Pro before ultimately upgrading to a paid solution like Persefoni Pro+, which provides additional regulatory reporting features, including a footprint ledger. If a business has set a goal of net zero, a tool like Persefoni Advanced will provide additional features and functionality to support the decarbonization journey.

Ready to calculate your carbon footprint? Sign up for Persefoni Pro for free here. 

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