Post-war Sierra Leone has experienced a population explosion that has raised questions among rural farmers about the relationship between family size and poverty. Agricultural decline and the high cost of schooling are not prompting parents to articulate a desire for smaller families; rather, they highlight that the uncertainty around articulating the “right” number of children is unresolvable because the ability to send children to school is predicated on increasing agricultural outputs that decline precisely because population pressure has reduced soil fertility. Bolten and Marcantonio conclude that this renders family size the heart of a paradox, where there is no optimal number of children. **NOTE: This is a preprint version** of Bolten, Catherine and Richard Marcantonio. 2021. 'The Paradox of Planning: Agriculture, Schooling, and the Unresolvable Uncertainty of Ideal Family Size in Rural Sierra Leone.' *African Studies Review* 1, no.22. https://doi.org/10.1017/asr.2020.96