INTRODUCTION: Dementia is a leading cause of death and disability globally. Estimating total societal costs demonstrates the wide impact of dementia and its main direct and indirect economic components. METHODS: We constructed a global cost model for dementia, presenting costs as cumulated global and regional costs. RESULTS: In 2019, the annual global societal costs of dementia were estimated at US $1313.4 billion for 55.2 million people with dementia, corresponding to US $23,796 per person with dementia. Of the total, US $213.2 billion (16%) were direct medical costs, US $448.7 billion (34%) direct social sector costs (including long-term care), and US $651.4 billion (50%) costs of informal care. DISCUSSION: The huge costs of dementia worldwide place enormous strains on care systems and families alike. Although most people with dementia live in low- and middle-income countries, highest total and per-person costs are seen in high-income countries. HIGHLIGHTS: Global economic costs of dementia were estimated to reach US $1313.4 in 2019. Sixty-one percent of people with dementia live in low-and middle-income countries, whereas 74% of the costs occur in high-income countries. The impact of informal care accounts for about 50% of the global costs. The development of a long-term care infrastructure is a great challenge for low-and middle-income countries. There is a great need for more cost studies, particularly in low- and middle-income countries. Discussions of a framework for global cost comparisons are needed.