Abstract Indian Standard I-Sections consist of some sections of the same designation but of different unit weights. The only major change in geometry indicated in SP:6(1)-1964 in these sections is the web thickness. The areas of such sections have been calculated by applying the corrections to the flange widths, considering the details of manufacturing process of such rolled steel sections given in IS 808 -1989 (Reaffirmed 1989). It is found that the area of only one such I-Section, namely, ISWB600 @ 145.1 kg/m, of this category, is differing from the area given in SP:6(1)-1964. It has also been found that the area of this section perfectly matches with the area given in SP: 6(1)-1964, if the correction to flange width due to the manufacturing process is neglected. Index Terms: SP: 6(1)-1964, IS 808-1989, I – Sections with multiple unit weights, Correction to flange width. Cross Sectional Areas