Scope 1, 2, 3 GHG Emissions Calculator

Enter your organization's energy use, fuel consumption, and supply chain activity to calculate your Scope 1, 2, and 3 greenhouse gas emissions following GHG Protocol standards. Input fields include natural gas use, electricity consumption, fleet fuel use, business travel, and purchased goods spend. You get back your total CO₂e emissions broken down by scope, helping you understand where your carbon footprint comes from and where to focus reduction efforts. Also try the Food Carbon Footprint Calculator.

therms/year

Annual natural gas consumption at your facilities (Scope 1)

gallons/year

Annual distillate fuel oil or diesel burned on-site (Scope 1)

gallons/year

Annual propane burned at your facilities (Scope 1)

gallons/year

Annual gasoline used by company-owned vehicles (Scope 1)

kWh/year

Annual purchased electricity for your facilities (Scope 2)

Select your grid region to apply the correct emission factor

passenger-miles/year

Total passenger-miles flown by employees for business (Scope 3)

miles/year

Total annual commute miles driven by all employees (Scope 3)

USD/year

Annual spend on purchased goods and services for spend-based Scope 3 estimation

tons/year

Annual solid waste sent to landfill from your operations (Scope 3)

Results

Total GHG Emissions

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Scope 1 Emissions (Direct)

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Scope 2 Emissions (Indirect Energy)

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Scope 3 Emissions (Value Chain)

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Scope 1 Share

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Scope 2 Share

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Scope 3 Share

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Results Table

Frequently Asked Questions

What is the difference between Scope 1, 2, and 3 emissions?

Scope 1 covers direct greenhouse gas emissions from sources owned or controlled by your organization, such as on-site combustion and company vehicles. Scope 2 covers indirect emissions from purchased electricity, heat, or steam. Scope 3 encompasses all other indirect emissions across your value chain — from employee commuting and business travel to purchased goods, services, and waste disposal. See also our Carbon Budget Calculator.

What GHG Protocol standard does this calculator follow?

This calculator follows the GHG Protocol Corporate Accounting and Reporting Standard, which is the world's most widely used greenhouse gas accounting framework. Emission factors are sourced from the EPA's Inventory of U.S. Greenhouse Gas Emissions and Sinks and IPCC AR5 global warming potential values.

Who should use a Scope 1, 2, 3 emissions calculator?

Any organization looking to measure, report, or reduce its carbon footprint should complete a GHG inventory. This includes businesses responding to investor ESG questionnaires, companies setting Science Based Targets (SBTi), those reporting to CDP, or organizations preparing sustainability reports under GRI or TCFD frameworks.

What emission factors are used in the calculations?

Natural gas uses 53.06 kg CO₂e per million BTU (EPA). Fuel oil uses 10.21 kg CO₂e per gallon. Propane uses 5.72 kg CO₂e per gallon. Gasoline uses 8.887 kg CO₂e per gallon. Electricity factors vary by grid region based on EPA eGRID data. Air travel uses 0.255 kg CO₂e per passenger-mile. Commuting uses 0.404 kg CO₂e per vehicle-mile. Purchased goods use a spend-based factor of 0.5 kg CO₂e per USD. Waste uses 0.52 metric tons CO₂e per ton landfilled. You might also find our Lifecycle Carbon Assessment Calculator (LCA) useful.

How do I reduce my Scope 3 emissions?

Scope 3 reductions typically require supplier engagement, shifting to lower-carbon purchased goods and services, enabling remote work to cut commuting emissions, replacing air travel with virtual meetings, and improving product end-of-life management. Since Scope 3 often represents 70–90% of a company's total footprint, it's where the greatest reduction opportunities exist.

What is a metric ton of CO₂ equivalent (tCO₂e)?

A metric ton of CO₂ equivalent (tCO₂e) is the standard unit for measuring greenhouse gas emissions. It expresses the warming impact of different gases (methane, nitrous oxide, etc.) relative to carbon dioxide using Global Warming Potential (GWP) values from the IPCC. This allows all gases to be reported on a single comparable scale.

Do I need to report all three scopes?

GHG Protocol requires companies to report Scope 1 and Scope 2 emissions and strongly encourages Scope 3 reporting. Many reporting frameworks and investor questionnaires (CDP, TCFD, SBTi) now expect Scope 3 disclosure, particularly for the most material categories relevant to your industry.

How accurate is the spend-based method for Scope 3 purchased goods?

The spend-based method is an approximation that uses a dollar-spent-to-emissions ratio. It's the most accessible approach when supplier-specific data isn't available, but it has lower accuracy than activity-based methods. For a more precise Scope 3 Category 1 figure, collect primary data from your top suppliers or use industry-average physical emission factors.