Knowledge of species-specific patterns of energy use is important for understanding the evolution of life histories as well as for determining how species might respond to alterations in environmental conditions. We measured standard metabolic rates (SMRs) in 59 Eastern Box Turtles (mass range = 106−510 g) and determined how differences in body mass and body temperature (20°C vs. 30°C) influenced SMRs. Rates of standard metabolism were significantly influenced by body mass at body temperatures of 20°C and 30°C and SMR was significantly higher at 30°C (Q₁₀ = 3.04). There was significant among-individual variation in SMR and individuals with higher metabolism at 20°C also tended to have higher metabolism at 30°C.