This paper uses household surveys from 89 countries to estimate the rate of extreme poverty among children in the developing world. The estimates are based on the same surveys and welfare measures as official World Bank poverty estimates. Of children under age 18 years, 19.5 percent are estimated to live on less than $1.90 per day, as opposed to 9.2 percent of adults ages 18 and above. Poverty rates are high for children ages 0 to 4 years, slightly higher among ages 5 to 9 years, and steadily decline for successively older age groups. The analysis also examines the sensitivity of age-based poverty estimates to the use of alternative household equivalence scales when adjusting the international poverty line accordingly. Child poverty rates remain above 17 percent, and are greater than adult poverty rates, for all reasonable two-parameter equivalence scales.