BACKGROUND: The 2-min walk test (2MWT) has been used in several health conditions, but the interpretation of its results is limited due to a lack of reference values. The aim of this study was to establish a reference equation to predict the distance walked (DW) in the 2MWT for healthy adults and the elderly and to test its reproducibility. METHODS: We evaluated 390 healthy subjects (195 male), 18-89 y old, with normal spirometry and no history of previous chronic diseases. Two 2MWTs were performed on the same day, 30 min apart. To test the reliability of the prediction equation, 70 subjects (35 male) were prospectively included in the study. RESULTS: Men walked farther than women (221 [202-240] vs 199 [164-222] m, respectively; P < .0001). Significant correlations were observed between DW and age (r = -0.50), weight (r = 0.23), height (r = 0.40), and gender (r = 0.35) (P < .001 for all). Age and gender persisted in the model to predict DW (R(2) = 0.51). There was no difference between the DW by the subjects (197 [182-216] m) and that estimated by the prediction equation (197 [179-222] m) (P = .68). CONCLUSIONS: We established a prediction equation that may be used as a reference to interpret performance on the 2MWT of adults and the elderly with different health conditions.