This study was carried out on 621 schoolboys with age range of 12-17 years in Junior and Senior Secondary Schools in Odeda area of Odeda local government in Ogun State, Nigeria. Different anthropometric data were collected from these boys. It was observed from the results that all anthropometric dimensions of the school children increase with their age. Moreover, there exists a little difference between mean values of different anthropometric dimensions between the boys of 12-13 years (2.9% to 8.8%), 14-15 years (1.3% to 9.9%), and 16-17 years (1.4% to 5.5%). But the said differences become much higher (16.2% to 42.4%) when the same were compared between the children of 12 years and 17 years. Therefore, it can be said that the design of furniture for the children of 12 years will not match the children of 17 years. If single furniture is designed by considering dimensions of the children from 12 years to 17years, it will also not suit the children of all age groups. Therefore, in the present investigation, all the students have been divided into three combined age groups, e.g., 12-13 years, 14-15 years, and 16-17 years, and the percentile values (5th, 50th and 95th) of anthropometric measures, which will be helpful for designing of the classroom furniture.