Product design and development are essential for a circular transition. Circularity decisions, such as those concerning the type of material, assembly method, and expected lifespan, made during the early design stages will significantly influence a product’s quality, cost, esthetics, sustainability, and circularity performance over the product lifecycle. However, circularity is not often considered in the early stages of product design and development. This paper presents the development of the concept circularity evaluation tool (CCET), which aims to support the evaluation of alternative product concepts in terms of their circularity potential in the early stages of product design and development. The CCET was iteratively developed based on an extensive literature review of the success criteria for tool development, guidelines, and existing tools for circular product design and development and strong collaboration with manufacturing companies. The tool was tested and verified at four manufacturing companies in Nordic countries. The tool has been proven useful for evaluating the circularity of products and supportive in the decision-making process in the early stages of product design and development.