GHG Protocol Calculator

About the GHG Protocol Calculator

The Greenhouse Gas Protocol is the world's most widely used corporate carbon accounting standard. It requires organizations to quantify emissions across three scopes: Scope 1 (direct), Scope 2 (purchased electricity), and Scope 3 (value chain). Together, these scopes provide a comprehensive picture of an organization's climate impact.

This GHG Protocol Calculator combines all three scopes into one worksheet. Enter your Scope 1 direct fuel emissions, Scope 2 electricity emissions, and Scope 3 value chain estimates. The calculator shows each scope's contribution, total emissions, and the breakdown as a percentage.

Use This calculator for initial GHG inventories, annual tracking, target-setting, and preparing data for CDP, SBTi, or regulatory disclosure.

Tracking this metric consistently enables energy professionals and facility managers to identify consumption trends and implement efficiency improvements before costs escalate unnecessarily. This measurement provides a critical foundation for energy auditing and sustainability reporting, helping organizations meet regulatory requirements and voluntary environmental commitments.

When This Page Helps

A complete GHG inventory is the starting point for corporate climate strategy. This calculator combines all three scopes in one place so you can see Complete View and understand where to focus reduction efforts.

How to Use the Inputs

1. Enter Scope 1 emissions (direct fuel combustion) in tonnes CO2.
2. Enter Scope 2 emissions (purchased electricity) in tonnes CO2.
3. Enter Scope 3 emissions (value chain) in tonnes CO2.
4. View total emissions and scope-by-scope breakdown.
5. Use results for target-setting and disclosure.

Example Calculation

Tips & Best Practices

• Most companies find Scope 3 is 70–95% of their total footprint.
• Start with Scope 1 and 2 (easier data) before tackling Scope 3.
• Track year-over-year to show reduction progress.
• Normalize by revenue (tonnes/$M) for intensity metrics.
• Set absolute and intensity targets aligned with science.
• Use this calculator annually to update your inventory.
• Consider third-party verification for credibility.

Why Full-Scope Accounting Matters

Looking at only Scope 1 and 2 can be misleading. A software company may have tiny direct emissions but massive Scope 3 from cloud computing, employee travel, and hardware supply chains. Full-scope accounting reveals the true picture.

The Path to Net Zero

Net zero requires reducing total emissions (all scopes) by at least 90% and neutralizing the remainder with permanent carbon removal. This is a much higher bar than carbon neutral, which allows offsetting. Start with a complete inventory to understand the gap.

Reporting Frameworks

Major frameworks requiring or recommending GHG inventories include CDP, TCFD, SEC climate rules, EU CSRD, SBTi, and RE100. Aligning your inventory with GHG Protocol ensures compatibility with all of them.

Frequently Asked Questions

• What is the GHG Protocol?

  The GHG Protocol, developed by WRI and WBCSD, is the most widely used international standard for corporate GHG accounting. It provides guidance on what to measure, how to set boundaries, and how to report emissions across Scope 1, 2, and 3.

• Do I need to report all three scopes?

  Scope 1 and 2 are always required. Scope 3 is required for SBTi targets and recommended by CDP and other frameworks. Even if not mandated, understanding Scope 3 reveals the largest reduction opportunities.

• What units should I use?

  The GHG Protocol reports in metric tonnes of CO2 equivalent (tCO2e). CO2e includes CO2, CH4, N2O, and F-gases converted using Global Warming Potentials. For most organizations, CO2 is the dominant gas.

• How do I set a reduction target?

  The Science Based Targets initiative (SBTi) provides methods for setting targets aligned with 1.5°C or well-below 2°C pathways. Typical targets are 42% reduction by 2030 (Scope 1+2) and 25%+ for Scope 3.

• What is an intensity metric?

  An intensity metric normalizes emissions by a business metric: tonnes per $M revenue, per employee, per unit produced, or per square foot. Intensity targets allow companies to grow while reducing emissions per unit of output.

• How often should I update my inventory?

  Annually is standard for most reporting frameworks. Quarterly updates enable faster management response. Real-time monitoring is emerging for energy-intensive operations.