Beam Shear Force Calculator
| Span (m) | Load (kN/m) | Max Shear (kN) | Total Load (kN) |
|---|---|---|---|
| 3 | 4 | 6 | 12 |
| 4 | 5 | 10 | 20 |
| 6 | 7 | 21 | 42 |
| 8 | 3 | 12 | 24 |
Formula for a uniform distributed load
For a simply supported beam carrying a constant distributed load over a span of length , each support carries half of the total load. The reaction shear at either end is therefore , while the total distributed load equals . Because the shear diagram is linear for a uniform load, the maximum value always appears at the supports.
Converting shear to average shear stress requires dividing by the area that resists shear. For rectangular beams a rough estimate is where represents the effective web area. The table above highlights how the reaction scales with span and loading so you can quickly sanity-check hand calculations or software output.
Interpreting the results
The calculator reports both the shear reaction and the total load applied to the beam. Designers often compare the shear value with allowable limits for wood webs, steel stiffeners, or concrete stirrups. If the reaction is close to a materialโs limit, consider shortening the span, reducing the load, or adding intermediate supports. The results are also helpful for sizing bearings and anchor bolts that must transfer the reaction safely into columns or walls.
To round out your analysis, combine this tool with the Beam Bending Stress Calculator, Beam Deflection Calculator, and Concrete Beam Shear Capacity Calculator. Together they create a quick checklist for verifying bending, deflection, and shear performance under the same loading scenario.