Scaling studies on phenotypic characteristics like birth mass are useful to understanding life history attributes within species. The wide range in body mass of elk (Cervus elaphus) in North America and Europe allows robust estimation of scaling relationships. Our goal was to estimate the scaling relationship of maternal body mass and offspring birth mass. Data were extracted from the literature, which included captive elk fed a readily digestible diet rich in nutrients. The mass of the mother at birth and the birth mass of the young were recorded for 11 groups of mothers and their offspring. A simple linear regression was used to estimate an allometric relationship between maternal body mass and offspring birth mass (R²  =  0.90). Birth mass scaled to the 0.78 power of maternal body mass. Understanding scaling relationships affecting maternal investment might have implications for understanding body size variation across the geographic range of elk.