As part of a series of studies addressing schoolbag carriage, two studies were carried out with the objective of providing evidence for a recommended upper schoolbag weight. Sixteen boys were firstly exposed to a simulated school day, while carrying schoolbags of differing loads and shoulder strap adjustments. Student’s posture changed proportionately with load. The magnitude of self reported measures of muscular strain and musculoskeletal discomfort (MSD) suggested that 15% BW may be excessive while 10% BW may be acceptable to school students. In the second study, a psychophysical approach demonstrated that student’s mean (SD) maximum acceptable schoolbag weight was 10.2(3.8)% BW. The results of these studies support current schoolbag weight recommendations. However, the results of other studies suggest that other schoolbag factors such as design, adjustment, carriage duration and mode also need to be considered when developing schoolbag carriage guidelines.