Welcome to Steel Beam Calculator. Below is our free Steel Beam Calculator with a beam span length fixed at 3 feet which you can try out for free, our full version is available from $40 and allows users to design and check simply supported W Beams, S Beams and American Standard Channels for any length span.elcome to Steel Beam Calculator. Below is our free Steel Beam Calculator with a beam span length fixed at 3 feet which you can try out for free, our full version is available from $40 and allows users to design and check simply supported W Beams, S Beams and American Standard Channels for any length span.