The GZA Scope 3 Calculator
Our goal is to remove the barriers organizations face in addressing the climate change impact from their value chain. With that goal in mind, we built our Scope 3 Calculator as a simple to use, affordable, and easy to deploy application for any size organization without specialized training.
Introducing the GZA Scope 3 Calculator
The latest version of our Calculator enables users to evaluate and assess the greenhouse gas (GHG) emissions from upstream Scope 3 activities (Categories 1 – 8) and several downstream Scope 3 categories (Categories 13 – 15) all in one streamlined and easy-to-use Excel-based tool.
The GZA Scope 3 Calculator uses transparent calculation methods in alignment with GHG Protocol guidance and can serve as a fundamental first step in your organization’s Scope 3 journey. It was built with real-world users in mind, from small enterprises to global corporations.
More than 600 unique companies, municipalities, institutions, and other organizations - located across the world - have used the GZA Scope 3 Calculator to evaluate their Scope 3 GHG emissions.
Download the GZA Scope 3 Calculator
You can download the Preview Version for free, or purchase the Full Version for $5,000 USD. To proceed with either option, please review and accept the Terms and Conditions below. For questions or alternate purchasing options, contact us at sustainability@gza.com.
Scope 3 Categories Covered by the Calculator
UPSTREAM
- ✓ 1. Purchased Goods and Services
- ✓ 2. Capital Goods
- ✓ 3. Fuel- and Energy-Related Activities
- ✓ 4. Upstream Transportation and Distribution
- ✓ 5. Waste Generated in Operations
- ✓ 6. Business Travel
- ✓ 7. Employee Commuting
- ✓ 8. Upstream Leased Assets
DOWNSTREAM
- ✗ 9. Downstream Transportation and Distribution
- ✗ 10. Processing of Sold Products
- ✗ 11. Use of Sold Products
- ✗ 12. End-of-Life Treatment of Sold Products
- ✓ 13. Downstream Leased Assets
- ✓ 14. Franchises
- ✓ 15. Investments
Supply Chain Activities | Categories 1 through 6
The Calculator uses the United States Environmentally-Extended Input Output (EEIO) emissions factors to correlate supply chain purchases with the associated life cycle emissions of each purchase. Each factor is automatically adjusted to account for currency inflation and the decarbonization of the US electric grid over time, from 2012 (the base year of the EEIO data) to 2025.
Employee Commutes | Category 7
Evaluating GHG emissions from employee commuting can seem like a straightforward task. However, it can become time-consuming and complex process when one considers the many variables needed to complete these calculations. The GZA Calculator has simplified this process by transparently compiling research and survey data for (1) average commuting distances and (2) personal vehicle well-to-wheel emissions from over 25 sources and covering more than 50 countries.
Upstream Leased Assets, Downstream Leased Assets, and Franchises | Categories 8, 13, and 14
If your organization operates leased assets or franchises, the most common source of emissions in those Scope 3 categories are related to energy consumption in buildings. The GZA Calculator allows users to easily evaluate those emissions by providing a wide range of building energy intensity values for multiple countries, climate zones, and building types. Simply provide the building size, location, and type (e.g., office, warehouse, retail, etc.) to receive automated energy consumption and Scope 3 emissions results.
Investments | Category 15
The Investments category can be difficult to evaluate given the various types of investment activities organizations may have and the unique calculation steps and boundaries that should be considered. This Calculator simplifies the process using spend-based EEIO emissions factors which enable users to estimate the Scope 1, Scope 2, and upstream Scope 3 emissions of each investment based on each investment’s revenue and your organization’s percent stake.
Scope 3 Summaries and Charts - Automatically Generated
The GZA Scope 3 Calculator gives your organization instant insights into your Scope 3 emissions through a variety of functions and features:
• Automated summaries of your value chain’s GHG emissions, sorted by their Scope 3 category
• Hotspot analyses of supply chain emissions, sorted by user-defined suppliers and categories
• Insights into the major industry groups where emissions are occurring in your supply chain
• Resources and links to Scope 3 guidance
• Recommendations to help your organization continue to address its Scope 3 impact
Frequently Asked Questions
The GZA Scope 3 Calculator is a Microsoft Excel-based tool that employes Visual Basic Macros to create a simplified and user-friendly experience.
Scope 3 calculations can comprise of thousands, even tens of thousands, of unique data points (especially for supply chain data) which are commonly available in a CSV or Excel format. Formatting and transferring this data into an Excel-based tool thus simplifies the calculation processed, as opposed to having to manually enter or upload each data point.
We highly recommend that users download the Preview Version of the Calculator for a detailed overview on what activity data is required to complete their organization’s Scope 3 emissions calculations.
• The supply chain emissions calculations will require your organization’s supply chain spend (i.e., spend with Tier 1 suppliers) broken down by purchase description and/or supplier, which will then allow you to select the Environmentally-Extended Input-Output emissions factors that are most applicable to each purchase.
• The employee commuting calculations will require your organization’s employee headcount, by country, and broken down by the typical weekly commuting schedule for each employee (e.g., 5 days per week, 3 days per week, remote worker, etc.).
• The leased asset calculations will require a list of your organization’s facilities (which do not fall under Scope 1 and Scope 2 reporting). Users must indicate the location, size, and building type for each facility.
• The investments calculations will require details on your organization’s equity and debt investments, which can include annual investment amounts, equity shares in each investment, and the industry type of each investment.
The GZA Scope 3 Calculator was designed using methodologies provided by the GHG Protocol Corporate Value Chain (Scope 3) Standard. Regardless, users must consider the reporting criteria of their disclosure program(s) before using information or following the recommendations provided by the GZA Scope 3 Calculator.
The methodologies used by the Calculator are intended to serve organizations who are calculating Scope 3 emissions for the first time or who are looking to use secondary approaches to evaluate their Scope 3 emissions. Most often, the Calculator helps organizations faced with the challenge of collecting more robust activity data such as supplier surveys or life cycle assessments.
The SBTi Corporate Near-Term Standard and Corporate Net-Zero Standard indicate that companies must follow the GHG Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard when calculating their Scope 3 emissions. As the methodologies used by the GZA Scope 3 Calculator are aligned with GHG Protocol guidelines, it can be used by organizations to develop a Scope 3 Inventory in support of submissions and reporting to the SBTi.