How do you measure the impact of a song or a sculpture on climate adaptation or social inclusion? That is the question driving our Cultural Sustainability Index. Developed in partnership with universities, statisticians and cultural practitioners, the index combines quantitative indicators—such as jobs created, carbon footprint reduced and number of women leaders trained—with qualitative assessments of empowerment, heritage preservation and narrative change. Our first edition will serve as a benchmark for funders, governments and civil‑society organisations seeking to invest wisely in cultural initiatives. By making the intangible tangible, we hope to prove beyond doubt that culture is a smart, necessary investment.