From 1992 to 1996, camel calves under one year of age from 20 herds and traditionally raised in the pastoral zone of Niger were individually monitored for zootechnical data. The study aimed at establishing a simple barymetric formula to estimate the weight of camel calves and modelizing weight gain taking into account some variation factors. Allometric data (live weight, height at withers, chest girth) were analyzed by the linear mixed model method. A barymetric formula was established from the measure of chest girth (CG) comprised between 0.7 and 1.5 m. Sex appeared as a significant factor of variation (P < 0.01): with the same CG, females were heavier than males at birth, then from CG = 0.9 m it was reversed. Predicted live weights varied between 30.56 ± 3.71 and 174.02 ± 3.01 kg in males and 32.37 ± 3.67 to 168.80 ± 2.90 kg in females. A growth model was calculated for camel calves aged 5 to 180 days. No sex effect or vermifugation effect of the mother in the 500 days before parturition (sign of nutrition and health states) were found. On the other hand, camel calves born during the rainy season or at the beginning of the dry season were 10% heavier and grew 10% faster than those born during the hot dry season (P < 0.01). Average daily gains were low with 318 and 289 g/d in the favorable and unfavorable seasons, respectively, typical of extensive farming systems.