Estimate the maximum preliminary point-load or uniformly distributed load based on steel bending strength, shear strength and a selected deflection limit.
What does steel beam load capacity mean? It is the load a beam can theoretically carry under a specified loading arrangement before a selected bending, shear or deflection limit is reached.
Why are there three different capacities? A beam can be limited by bending strength, shear strength or serviceability deflection. The lowest applicable capacity is the controlling preliminary result.
What is Z? Z is the elastic section modulus. It connects bending moment and bending stress through the relationship σ = M/Z.
What is I? I is the second moment of area. It measures the beam's resistance to elastic bending deformation and is used in deflection calculations.
Why does a longer beam carry less load? A longer span produces larger bending moments and much larger deflections for the same applied load.
Does a higher-strength steel always increase beam capacity? It can increase material-controlled bending capacity, but other limits such as buckling, deflection, shear or connections can still control the design.
Why can deflection control a beam? A beam may remain below its strength limit while moving too much for its intended service. The selected deflection limit can therefore produce a lower allowable load.
Does this include the beam's own weight? No. The calculator treats the entered loading separately. Actual design should include beam self-weight and all other permanent and variable loads.
Can this choose an I-beam? No. It requires actual section properties. A real beam selection should use verified section data and complete structural design checks.