Objective Pediatric antiretroviral therapy (ART) for children with HIV (CHIV) must be dosed appropriately for children’s changing weights as they grow. To inform accurate estimates of ART formulations and doses needed, we described weight-for-age distributions among CHIV on ART in the IeDEA global pediatric collaboration between 2004 and 2016, using data from six regions (East, West, Central, and Southern Africa, Asia–Pacific, and Central/South America and the Caribbean). Results Overall, 59,862 children contributed to the analysis. Age and weight data were available from 530,080 clinical encounters for girls and 537,894 for boys. For each one-year age stratum from 0 to 15 years, we calculated the proportion of children in each of the weight bands designated by the World Health Organization as relevant to pediatric ART formulations: 0 to  < 3 kg, 3 to  < 6 kg, 6 to  < 10 kg, 10 to  < 14 kg, 14 to  < 20 kg, 20 to  < 25 kg, 25 to  < 30 kg, 30 to  < 35 kg, 35 to  < 40 kg, 40 to  < 45 kg, 45 to  < 50 kg, 50 to  < 55 kg, 55 to  < 60 kg, and ≥ 60 kg. Data are reported for the entire cohort, as well as stratified by sex and IeDEA region, calendar year of ART use, and duration on ART at time of assessment (< 12 or ≥ 12 months), provided in data tables. These data are critical to improve the accuracy of forecasting and procurement of pediatric ART formulations as the pediatric HIV epidemic and pediatric HIV treatment strategies evolve.Read less <