Scope 3 Emissions Calculator

Estimate indirect value chain emissions using the GHG Protocol methodology. Activity Data × Emission Factor = Emissions (tCO2e).

GHG Protocol15 CategoriesValue ChainFree
GHG Protocol standard
DEFRA & EPA factors
5 categories covered
Formula:Activity × Emission Factor = Emissions (tCO2e)
100,000 × 0.5 kg =50.00 tCO2e
Calculate Scope 3 Emissions
Select a category and enter your activity data

GHG Protocol Category 1 — Purchased Goods & Services

Emission factor: 0.5 kg CO2e / €(Spend-based factor (DEFRA / GHG Protocol))

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100,000€ spent×0.5=50.00 tCO2e
Scope 3 Emissions: Complete Guide
GHG Protocol, value chain emissions, and reporting frameworks

Scope 3 emissions are indirect greenhouse gas emissions that occur in a company's value chain but are not owned or controlled by the company itself. Defined by the GHG Protocol Corporate Standard, they span 15 categories across both upstream (supply chain) and downstream (customers, end-of-life) activities.

For most companies and sectors, Scope 3 represents the largest share of their carbon footprint — often 70–90% of total GHG emissions. This makes addressing Scope 3 essential for any meaningful net-zero strategy.

Our calculator covers five of the most commonly measured categories: purchased goods and services (Cat. 1), waste in operations (Cat. 5), business travel (Cat. 6), employee commuting (Cat. 7), and use of sold products (Cat. 11). We use simplified emission factors for quick estimation; for formal reporting, use official DEFRA, EPA, or industry-specific factors.

Emissions (kg CO2e) = Activity Data × Emission Factor

Activity data is the quantitative measure of the activity — for example: kilometres of business travel, euros spent on purchased goods, or tonnes of waste generated.

Emission factors convert that activity data into CO2 equivalent (CO2e) using standardised values. The GHG Protocol recommends using the most specific factors available.

Purchased goods: €100,000 × 0.5 kg/€ = 50 tCO2e

Business travel: 100,000 km × 0.25 kg/km = 25 tCO2e

Employee commuting: 50,000 km × 0.12 kg/km = 6 tCO2e

Waste (landfill): 10 t × 446 kg/t = 4.46 tCO2e

Sold products: 1,000 units × 2 kg/unit = 2 tCO2e

Upstream Activities (Categories 1–8)

1Purchased goods & servicesCovered
2Capital goods
3Fuel and energy-related activities
4Upstream transportation & distribution
5Waste generated in operationsCovered
6Business travelCovered
7Employee commutingCovered
8Upstream leased assets

Downstream Activities (Categories 9–15)

9Downstream transportation & distribution
10Processing of sold products
11Use of sold productsCovered
12End-of-life treatment of sold products
13Downstream leased assets
14Franchises
15Investments

Scope 1

Direct Emissions

From sources owned or controlled by the company. Examples: on-site combustion, company fleet, fugitive emissions.

e.g. Gas boiler, owned trucks

Scope 2

Indirect Energy

Indirect emissions from the generation of purchased electricity, heat, steam, or cooling consumed by the company.

e.g. Purchased electricity

Scope 3

Value Chain

All other indirect emissions across the full value chain — upstream supply and downstream customer use.

e.g. Suppliers, commuting, sold products

For EU compliance costs on Scope 1/2 emissions, see our EU ETS calculator or CBAM calculator.

Emission factors convert activity data into CO2 equivalent. The accuracy of your Scope 3 estimate depends heavily on using appropriate factors.

DEFRA (UK): Annual government conversion factors for company reporting — covers travel, waste, energy, water, materials.
US EPA: Emission Factors Hub — comprehensive US-specific factors for fuel combustion, vehicles, waste.
GHG Protocol: Scope 3 Calculation Guidance and sector-specific tools. Foundation of all major reporting frameworks.
ecoinvent: LCA database with product-level emission factors for detailed, supply-chain specific analysis.

For CDP, CSRD, or SBTi disclosures, our simplified factors are a starting point only. Formal submissions require primary supplier data or official conversion factors.

Frequently Asked Questions

Scope 3 emissions are all indirect greenhouse gas emissions that occur in a company's value chain but are not owned or controlled by the reporting company. The GHG Protocol Corporate Standard defines 15 Scope 3 categories — covering everything from purchased goods and business travel to the use of sold products and investments. Scope 3 typically represents 70% or more of a company's total carbon footprint.

Emissions (kg CO2e) = Activity Data × Emission Factor. Activity data is the quantitative measure — for example, kilometres of business travel, euros spent on purchased goods, or tonnes of waste generated. Emission factors (in kg CO2e per activity unit) convert activity data into CO2 equivalent. Example: 100,000 km business travel × 0.25 kg CO2e/km = 25,000 kg CO2e = 25 tCO2e.

Upstream (Categories 1–8): 1. Purchased goods & 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 (Categories 9–15): 9. Downstream transportation, 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.

Scope 1 covers direct emissions from sources owned or controlled by a company — such as combustion in company-owned boilers and vehicles. Scope 2 covers indirect emissions from purchased electricity, heat, steam, or cooling. Scope 3 covers all other indirect emissions across the entire value chain — both upstream (supply chain, purchased goods) and downstream (customer use, end-of-life). For EU compliance emissions costs, Scope 1 and 2 are most directly subject to EU ETS and CBAM.

Key sources include: DEFRA (UK) which publishes annual conversion factors (e.g. DEFRA 2024: average car = 0.17 kg CO2e/km, general waste to landfill = 446 kg CO2e/tonne); the US EPA's Emission Factors Hub; the GHG Protocol Scope 3 Calculation Guidance (using EEIO models for spend-based factors); and lifecycle databases such as ecoinvent. Our calculator uses simplified factors for quick estimation. For CDP, CSRD, or SBTi disclosures, use official or supplier-specific datasets.

Scope 3 reporting is increasingly required. In the EU, the Corporate Sustainability Reporting Directive (CSRD) requires large companies to report Scope 3 under European Sustainability Reporting Standards (ESRS E1) from 2025 (for FY2024). The Science Based Targets initiative (SBTi) requires companies to set Scope 3 targets if Scope 3 exceeds 40% of total emissions.

For most companies, Scope 3 emissions are far larger than Scope 1 and 2 combined — often 70–90% of total GHG footprint. Without addressing Scope 3, companies cannot achieve genuine net-zero. The SBTi Net-Zero Standard requires addressing the entire value chain to align with a 1.5°C pathway.

Key strategies: engage suppliers to measure and reduce their emissions (Category 1); design products for energy efficiency and longer use (Category 11); support employees with public transport or remote work (Category 7); reduce business travel through virtual meetings (Category 6); improve waste management and circular economy practices (Category 5). Scope 3 reduction requires supplier engagement programs and science-based target setting.
Emission Factors Used
Simplified factors for estimation

Purchased Goods & Services

Category 1

0.5 kg CO2e / €

Business Travel

Category 6

0.25 kg CO2e / km

Employee Commuting

Category 7

0.12 kg CO2e / km

Waste in Operations

Category 5

446 kg CO2e / tonne

Use of Sold Products

Category 11

2 kg CO2e / unit
Quick Examples
€100k goods50.0 tCO2e
100,000 km travel25.0 tCO2e
50,000 km commute6.0 tCO2e
10 t waste (landfill)4.46 tCO2e
1,000 products sold2.0 tCO2e
Reporting Frameworks
GHG Protocol — Foundation standard, 15 categories
SBTi — Scope 3 required if >40% of footprint
CDP — Annual Scope 3 disclosure questionnaire
CSRD / ESRS E1 — EU mandatory from 2025 (FY2024)
TCFD — Recommends Scope 3 disclosure
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