Integration of 10R principles into CIRCLE as an innovative tool for assessing circular economy

Abstract

This paper introduces the Circular Index for Resource Conservation and Loop-based Economy (CIRCLE), a novel metric designed to assess circular economy performance. Grounded in the 10R hierarchy, CIRCLE employs a structured point-based system (0–3) to evaluate practices across all R-principles, with particular emphasis on the often-overlooked dimensions of Rethink, Repurpose, and Resell. Unlike prior models, it enables a more granular and comprehensive assessment of resource efficiency, innovation, and value recovery. Adaptable across industries, systems, and scales, CIRCLE establishes clear scoring criteria, integrates theoretical foundations, and validates its applicability through three real-world case studies. These applications demonstrate the tool's capacity to distinguish levels of circular performance, identify sustainability gaps, and guide targeted interventions. CIRCLE is available as a user-friendly free tool at bit.ly/CIRCLE2026. By offering a standardized yet flexible framework, CIRCLE advances circularity assessment and provides a practical decision-support tool for sustainability science, industrial ecology, and policy development.