This brief paper follows the broad methodological approach of the two previous SDG 4 costing exercises and their main assumptions (UNESCO, 2015a; UNESCO, 2020). It introduces the SDG 4 benchmarking process and how to estimate the cost of achieving these targets set by countries, largely based on their sector plans. Finally, it presents the revised assumptions of the model and the key findings. Despite lowering ambition, there is still an average national financing gap of USD 78 billion per year in the 44 low- and lower-middle-income countries in Africa.