jats:titleAbstract</jats:title>jats:pCurrent design approaches to determine the capacity of plates in local buckling are based on empirical equations, in particular the widely used Winter equation. In contrast, this research presents a novel analytical approach, focusing on outstand steel plates. The derivation of the method is rooted in the Föppl‐von Karman equations, which are first simplified by making a number of basic mechanical assumptions about the post‐buckling stress field. An approximate solution to the emerging differential equation is obtained, which assumes a polynomial displacement profile in the transverse direction of the plate. This solution agrees eminently well with the results of finite element simulations, both for the case of a geometrically perfect plate and a plate containing an initial imperfection. By combining the obtained post‐buckling stress profile with a failure criterion based on von Karman's effective width concept, a closed‐form strength equation for compressed outstand plates is derived, which is seen to be a sole function of the plate slenderness and a dimensionless imperfection factor. This equation agrees closely with the available experimental data.</jats:p>