Normally, I use the 3x3 lowpass filter if I need to filter a DEM. However in one case, for better results in curvature calculations, I would like to do 5x5 filtering. How is this possible in ArcGIS 10.3?
You can use the Focal statistics tool and choose your 5x5 there or create your own kernel for it. Low-Pass is quite easy as it is just the mean which can be chosen for this tool as well.