Fast beam shear checks for typical site loading cases. Exportable results. Clear sign convention. Practical units. Reliable reactions. Consistent reporting. Verified math every time.
White theme Simply supported beam Point loads + UDLThe beam is treated as simply supported with vertical reactions at both ends. All enabled loads are assumed downward, and reactions act upward.
Positive shear follows your selected sign convention for the left face.
| Case | Span L (m) | Point Loads | UDL w (kN/m) | UDL Range (m) | Section x (m) | R1 (kN) | R2 (kN) | V(x) (kN) |
|---|---|---|---|---|---|---|---|---|
| Example A | 6 | P1=12 kN at 2 m | 2 | 0 to 6 | 3 | 10.00 | 14.00 | −8.00 |
| Example B | 5 | P1=8 kN at 2 m; P2=6 kN at 4 m | 0 | — | 3 | 6.40 | 7.60 | −1.60 |
| Example C | 4 | — | 3 | 1 to 4 | 2 | 4.88 | 4.12 | 1.88 |
Example values are illustrative; verify assumptions for your design case.
Shear force is the internal “sliding” action that develops when loads try to move one part of a beam past another. On site, shear commonly governs near supports and at load introduction points, where diagonal cracking, web crushing, and connection distress can begin.
Practical checks start with span length, load magnitudes, and their locations from the left support. This tool handles three point loads and a UDL segment, matching common cases like equipment, stacked materials, and floor loading. Include self-weight only if it is not already in your load schedule and confirm tributary width for line loads.
Reactions come from balancing forces and moments. For example, a 12 kN point load at 2 m contributes 24 kN·m about the left. A 2 kN/m load over 6 m totals 12 kN acting at 3 m. Conversions keep units consistent through the calculation.
Once reactions are known, shear at a section equals the left reaction minus all loads to the left of that section. Because drawings and standards vary, you can choose whether positive shear on the left face is upward or downward.
Confirm that R1 + R2 equals total applied load. The shear diagram should step down by each point load. Under a full-span UDL, shear changes linearly with slope −w, and should approach zero near the far support (rounding aside). If numbers look odd, recheck units, load positions, and whether a load is enabled.
Peak shear typically occurs at a support or immediately next to a concentrated load. The calculator probes key locations around load points and UDL boundaries to estimate the maximum magnitude for quick review, supporting decisions on stirrup spacing, web reinforcement, and bearing checks.
Use it for screening lintels, temporary beams, joists under mixed loading, and quick QA checks. For cantilevers, fixed ends, or continuous spans, treat the output as preliminary and confirm with a full structural model.
CSV supports logs and spreadsheets, while the PDF provides a printable summary for site folders. Always record assumptions: support condition, load direction, and measurement references, plus the load case name, date, and checker initials, so reviewers can reproduce the check.
It assumes a simply supported beam with vertical reactions at both ends. It does not model fixed ends, cantilevers, or continuity across multiple spans.
Yes. Enable the UDL and enter start and end positions. The tool applies the load only over that segment and includes its centroid in the reaction calculation.
Reactions concentrate at supports to balance total applied load. Since shear starts from the reaction value, the largest magnitude often occurs at or near a support, especially under distributed loading.
Pick x at locations of interest: near supports, at load application points, at openings, or where detailing changes. For quick checks, evaluate x just to the left and right of point loads.
Negative means the calculated shear opposes your selected positive direction on the left face. If your office convention differs, switch the sign option to match your reporting.
No. The table is illustrative only. Your results depend on actual spans, loads, and support conditions. Always verify boundary conditions and load paths before design decisions.
The exports summarize key inputs and computed results. For a full audit trail, also save your load schedule and the assumed positions used during the check.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.