ABSTRACT The objective was to determine zoometric indices, correlate, and predict body weight based on the biometric measurements of F1 Dorper × Santa Inês (F1 D × SI) ewes created extensively. Were 25 F1 D × SI sheep monitored, with ages varying from 2 to 9 months. Body weight, thoracic perimeter, belly perimeter, body length, withers height, rump height, rump width, and rump length were measured on a monthly basis and zoometric indices were estimated from them. Descriptive data analysis, Pearson's correlation, and regression analysis were performed. The biometric measurements and zoometric indices of F1 D × SI ewes indicate an animal of aptitude for cutting, with good conformation. In addition, they demonstrate favorable aspects for reproduction, a fundamental characteristic in the selection of matrices. Body weight has a high and positive correlation for all characteristics analyzed, with values ranging from 0.74 of the rump length to 0.88 of the thoracic perimeter. The regressions for all biometric measurements were highly significant (P <0.0001) with an emphasis on the thoracic perimeter that has the highest coefficient of determination (R² = 0.77), the other measures presented below 0.70. It was concluded that F1 Dorper × Santa Inês ewes have characteristics for meat production and for reproduction. Also, of the biometric measurements, the thoracic perimeter can be used to predict the body weight of F1 Dorper × Santa Inês ewes.