This paper attempts to estimate the aggregate annual costs of child poverty to the US economy. It begins with a review of rigorous research studies that estimate the statistical association between children growing up in poverty and their earnings, propensity to commit crime, and quality of health later in life. We also review estimates of the costs that crime and poor health impose on the economy. Then we aggregate all of these average costs per poor child across the total number of children growing up in poverty in the United States to obtain our estimate of the aggregate costs of the conditions associated with childhood poverty to the US economy. Our results suggest that these costs total about $500 billion per year, or the equivalent of nearly 4% of gross domestic product (GDP). More specifically, we estimate that childhood poverty each year: (1) reduces productivity and economic output by an amount equal to 1.3% of GDP, (2) raises the costs of crime by 1.3% of GDP, and (3) raises health expenditures and reduces the value of health by 1.2% of GDP.