The relationship between child marriage and fertility can be due in part to the socio-economic and cultural context in which girls who marry early tend to live. But child marriage may also have a direct impact on fertility after controlling for socio-economic and cultural context. Marrying early is often associated with a lack of agency for girls, including in terms of access to family planning that can help delay or reduce births if women so desire. For societies, higher total fertility rates lead to higher population growth, lower growth in gross domestic product (GDP) per capita, slower poverty reduction, and difficulties for governments to provide basic services to a growing population. This brief estimates the impact of child marriage on the number of children that women have over their lifetime in Bangladesh, as part of a series of standardized briefs on this topic for multiple countries.