This paper presents the effect of geometry on the structural capacity of masonry arch bridges with different geometric features. This study was performed using an application (ANPAF) developed in MATLAB and based on the Linear Programming Method developed by Livesley. The geometry is read directly from an 'a.dxf' file, which stores the information obtained from planimetric surveying techniques. The results were compared with real and idealized geometry corresponding to each of the arches. This study aims to estimate the percentage of error that can occur in the structural assessment of masonry bridges by reading from different shapes as well as to estimate geometrical error. (C) 2012 Elsevier Ltd. All rights reserved.