Clothing fit is important to wearers on an everyday level and is frequently covered in clothing texts (Brown and Rice, 2001; Le Pechoux and Ghosh, 2002; Fan, Yu and Hunter, 2004), often with reference to the variables identified by Erwin, Kinchen and Peters (1979). Whilst these highlight important attributes of fit aesthetics, the fit of sportswear clothing can have a direct bearing on performance and potentially the outcome of the sports event. Fit can be considered in terms of function and comfort perception, but from a product development perspective fit can and should be engineered with consideration of how each variable interacts. Importantly, developments of 3D product development reinforce the geometry and numeric nature of product development and support the assertion for numerically understanding the garment and its fit (Gill, 2011). We would propose that wearer perception plays only a small part in engineering fit and that the following variables require careful and integrated consideration: fabric, function, sensorial comfort, performance expectations and ease determination, especially regarding their numeric application in terms of the pattern.