With the rapid pace of global urbanisation, cities play a crucial role in achieving global sustainability. However, they also present several significant challenges. Although there are extensive national and regional ecological footprint (EF) studies based on global and national databases, there is a noticeable gap in city-level EF studies, particularly in developing nations. This lack of local data has restricted the use of EF on a local scale. Therefore, we adopted a bottom-up EF approach to assess the urban sustainability of the PH metropolis. By tracking annual natural resource demand and using locally sourced consumption data, we estimated the city’s EF and compared it with the region’s biocapacity (BC). Findings reveal an estimated EF of 0.03 gha per capita and a biocapacity of 0.02 gha per capita, indicating an ecological deficit of 0.01 gha per capita, with the EF Index of -0.05 suggesting unsustainability. Results showed that food, built-up areas, and energy consumption were the primary drivers of urban unsustainability, accounting for 51.1%, 19.5%, and 9.1%, respectively. Our findings demonstrate that food, urbanisation, and energy consumption shape urban sustainability, contributing sector-specific insights for targeted policy intervention to advance urban sustainability in line with global sustainability action.