The non-linear flange curling phenomenon in cold formed profiles is the tendency of slender flanges to deform towards the neutral axis for increasing flexural curvature. Based on Braziers work, Winter proposed a simple engineering formula for determination of the local flange deformation towards the neutral axis. This formula is used in Eurocode to estimate flange curling deformation and give a limit after which flange curling has to be taken into account, however no method or procedure is given for this. The current work presents a new original method, which fits directly into the iterative scheme of Eurocode for determination of effective widths and the neutral axis position in flexure of thin-walled cross sections.