This resource from the American Institutes for Research introduces the Planning Tool for Developing a System for Thriving and Learning, a key component of the Science of Learning and Development (SoLD) Alliance. Aligned with the Guiding Principles for Equitable Whole Child Design, this tool is designed to assist educators in creating transformative learning environments. Focused on three essential action lenses—positive developmental relationships, rich learning experiences, and integrated support systems—the tool, accompanied by a rubric, equips decision-makers to evaluate existing and proposed programs, policies, structures, and practices. By applying insights into how students learn and thrive, the planning tool facilitates the development of equitable, effective, and transformative learning environments tailored to unique contexts, promoting a student-centered approach in education.