BackgroundIn Indonesia, nearly half of all children aged less than six months were not exclusively breastfed in 2017. This study aimed to compare the cost of providing direct or indirect exclusive breastfeeding 0–6 months, partial exclusive breastfeeding and commercial milk formula only. This study also assessed the maternal socioeconomic and mental health factors to providing exclusive breastfeeding.MethodsData were collected in 2018 via a cross-sectional survey of 456 mothers in Bandung City and Purwakarta District, West Java Province, Indonesia, who had children aged less than six months. We used micro-costing to calculate the cost of productivity, equipment, supplies, and training of mothers when providing direct exclusive breastfeeding, indirect exclusive breastfeeding, partial exclusive breastfeeding (a mix of breastfeed and commercial milk formula), and infant formula/commercial milk formula only. Logistic regression was used to determine the impact of several independent variables, including mother’s level of depression, on exclusive breastfeeding.ResultsTo provide direct exclusive breastfeeding, the cost per mother in the first six months is US$81.08, which is less expensive than indirect exclusive breastfeeding (US$171.15), partial exclusive breastfeeding (US$487.8) and commercial milk formula (US$494.9). We also found that education and age are associated with the decision to provide direct exclusive breastfeeding. Mothers who work will most likely provide indirect exclusive breastfeeding, commercial milk formula, or partial breastfeeding as opposed to direct exclusive breastfeeding. Finally, although severe depression symptoms have a positive relationship with the decision to provide commercial milk formula over direct exclusive breastfeeding, the evidence here is not strong.ConclusionsThe total cost of providing only commercial milk formula is 6-times higher than the cost of direct exclusive breastfeeding. The presence of severe depression symptoms is positively related to mothers opting for other feeding methods aside of direct exclusive breastfeeding and indirect exclusive breastfeeding. This study shows that direct exclusive breastfeeding is economically preferable to other methods, supports policies to reduce the time cost of exclusive breastfeeding (e.g., paid maternity leave and maternal cash transfers), and addresses the importance of mother’s mental health to ensure successful breastfeeding.