Abstract
We used four methods (direct count, indirect count, wisdom of the crowd, and unique object multiplier) to map and estimate the population size of street children in six major cities in Iran in 2017. In aggregate for the six cities, the number of street children was estimated at 5296 (interquartile range [IQR] 4122-7071) using the median of the four methods. This corresponds to a rate of 16.3 (IQR 12.5-24.5) per 10,000 children age 5-18 years old, or 3.2 (IQR 2.4-5.3) per 10,000 total population. The total number for street children in the country is estimated at 26,000 (IQR 20,239-34,719) children. Results can help policy-makers advocate for resources, plan programs, and evaluate the reach of programs for street children. The maps created through the course of the population size estimation exercise can also guide outreach efforts to provide street children with health and social welfare services.