Abstract Circular product design has been recognised in the academia as a foundational step for companies to make circular business models functional and viable. In this regards, it is vital to have a quick-and-easy practical toolkit providing diagnostics and specific guidelines on product design in terms of circularity performance. The present paper announces a Circular Product Design Toolkit (CPD Toolkit) under development now, which aims at enhancing the circularity potential of an existing product by redesign. The following objectives are addressed. First, a brief review of existing approaches in the field of product-level circularity metrics and also available circular product design tools to clarify their purpose and practical value is conducted. Second, the scientific approach to assess a product circularity performance, previously developed, as a methodological background of the CPD Toolkit is outlined. Third, the basic principles and building blocks of the CPD Toolkit are briefly set out with further discussion in terms of possible presentation of information block as actual product circularity dataset and guideline part dealing with specific instructions for a company on how to progress in the circularity of the product produced.