Introduction: Wistar rats are one of the most popular strains routinely used for research in the laboratory to serve as an important research tool, so it requires strict control of variables such as age, sex and body weight, and Thus to extrapolate the results to the human model. Objective: To develop reference curves for assessing the physical growth of male Wistar rats according to chronological age and somatic maturation from a noninvasive. Methodology: The subjects studied were 731 male Wistar rats transversely. We assessed age, body weight and body surface. LMS method was used to construct percentile curves based on weight and somatic maturation. Results: The proposed physical growth curves are used to track the physical growth and nutritional status diagnosis of male Wistar rats. Budgets by cutting points are: P3, P10, P25, P50, P75, P90 and P97. Conclusion: The results suggest that scientists from different areas can use such references, in order to extrapolate somatic growth phases of the laboratory rat and the human model is a non-invasive alternative to assess growth and nutritional status.