Engineering tolerance design plays an important role in modern manufacturing. In this paper, the Kapur's model was modified so that the economic specification limits for both symmetric and asymmetric losses can be established. Three different loss functions: (1) Taguchi's quadratic loss function; (2) Inverted Normal Loss Function; (3) Revised Inverted Normal Loss Function are compared in the economic tolerance design. The relationships between the three loss functions and process capability indices for symmetric tolerance are established. The results suggest that the revised inverted normal loss function be used in determination of economic specification limits