Calculate your full Scope 3 footprint across all 15 GHG Protocol categories using DEFRA 2025 emission factors. Free, browser-based, no signup required. ESRS E1-5 compliant output.
This calculator uses UK Government DEFRA 2025 GHG Conversion Factors for activity-based categories. For spend-based categories, it uses EEIO (Environmentally Extended Input-Output) factors. All factors are updated annually — always verify the current year version for formal reporting.
This tool produces spend-based and activity-based screening estimates — appropriate for initial materiality assessment and gap analysis. For CSRD/ESRS E1-5 compliance, you need documented methodology, supplier-specific data for material categories, and third-party limited assurance. ESGMaster provides the full compliance infrastructure.
The GHG Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard is the global framework for measuring indirect emissions across 15 categories. ESRS E1-5 mandates GHG Protocol methodology for all Scope 3 disclosures under CSRD. The GHG Protocol's own Scope 3 Evaluator tool was decommissioned in August 2023 — ESGMaster fills that gap.
Spend-based estimates (Categories 1, 2, 10, 14, 15) have ±50-100% uncertainty — use them for screening only. Activity-based estimates (Categories 3-9, 11-13) have ±20-40% uncertainty with good input data. Supplier-specific primary data (the gold standard) has ±5-10% uncertainty. Start with this tool to identify hotspots, then invest in primary data for top categories.