Free Online Multi-span Beam Calculator

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Welcome to the Multi-span Beam Calculator. A free, online multi-span beam calculator to generate shear force diagrams, bending moment diagrams, deflection curves and slope curves for beams with complex boundary conditions, multiple spans and multiple loads. Select a beam and enter dimensions to get started. Then scroll down to see shear force diagrams, moment diagrams, deflection curves, slope and tabulated results.

Material (E)
29,000,000 psi
Shape (Ix)
50 in4
Add Spans
1 Span
Add Loads
1 Load

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Comprehensive Reports

Easy to read, printable and comprehensive design reports. AISC Steel and NDS Wood Design LRFD and ASD Design Checks and Load Combinations.

About the Beam Bending Calculator

Beam Deflection Calculator

This calculator uses the finite element analysis method to calculate displacements, forces and reactions in multi span beams with multiple loads. The finite element analysis (FEA) method relies on Hook's law to find a highly accurate approximate solution to the beam. The model is discretized into small elements and a spring constant is established for each element. Forces (loads) are applied to the springs, a stiffness matrix (k) is generated from the small elements and the displacements are found by inverting the stiffness matrix and multiplying it by the force vector. Recall Hook's law for springs:


We extend this to 2 and 3 dimensions using linear algebra:

`|F| = [k]|x|`

Beam Moment and Shear Force Calculator

The multi-span beam calculator is a great tool to quickly validate forces in beams with multiple spans and load. Use it to help you design steel, wood and concrete beams under various loading conditions.

Steel, Wood and Concrete Beam Calculator

If you have a steel, wood or concrete beam with complex boundary conditions and loads this is a great tool for solving the problem numerically. If you'd like to validate this calculator use our closed-form beam calculator to compare results: Beam Calculator. If you need full design checks via AISC 360, NDS, ASD and LRFD for steel or wood beam design and you want to design your next beam in minutes, you might like our Beam Designer tool.

Free AISC Steel and NDS Wood Beam Design

Our goal with WebStructural is to give back to the engineering community by providing a free, cloud-based structural analysis software. There's nothing to install, simply navigate to one of our calculators like this one and start designing! If you like the tool and decide you'd like to save and print projects you can upgrade for $19 monthly. There's no long-term contract. Cancel anytime, we'll save your projects and you can resubscribe later to access them.

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