Welding-induced distortions are one of the major problems frequently encountered in industry. Different geometrical and welding process parameters are believed to influence distortions. One of the most common types of distortions frequently observed in butt-welded plates is angular distortion. In this study, the effect of geometrical parameters on angular distortions in butt-welded plates has been investigated numerically and experimentally. A comprehensive study has been performed, and several cases with different plate lengths, widths and thicknesses have been studied. Distortions have been predicted by three-dimensional thermo-elastic-plastic finite element simulation. The finite element results have been verified by a series of experimental measurements for temperatures and angular distortions. The results of this study revealed that plate thickness, length and width influence the magnitude and mode of distortions greatly. The results revealed that decreasing the plate thickness or increasing the weld length results in higher and nonlinear angular distortions. Increasing the plate width has an adverse effect and reduces the angular distortion. In addition, the thickness of the plate has a key role on distortion behavior and can lead to buckling in thin plates.