Beam Load Calculator
Use this beam load calculator to find the support reactions for a simply supported beam carrying one to ten vertical point loads.
Support Reactions
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Quick Answer: For a simply supported beam, the reaction at B equals the total moment of all loads about A divided by the span, and the reaction at A equals the total vertical load minus the reaction at B.
How to Calculate
- Enter the span: Provide the distance between support A and support B.
- Choose the number of loads: Add as many point loads as you need, up to ten.
- Enter load magnitudes and positions: Measure every load location from support A using the same length unit as the span.
- Read the reactions: The calculator returns the support reactions at A and B based on force and moment equilibrium.
Formula
R_B = sum(F_i x x_i) / L and R_A = sum(F_i) - R_B
| Variable | Meaning | Unit |
|---|---|---|
| R_A | Support reaction at A | force |
| R_B | Support reaction at B | force |
| F_i | Point load i | force |
| x_i | Distance of load i from support A | length |
Worked Examples
Two-load beam - Reactions from two point loads
- Span: 6 m
- Load 1: 10 kN at 2 m
- Load 2: 8 kN at 4.5 m
Result: R_B = 9.33 kN and R_A = 8.67 kN
The farther load contributes more moment to the reaction at support B.
Interpretation Table
| Range | Meaning | Action |
|---|---|---|
| Reaction at A larger | Loads are closer to support A overall | Check left-side bearing and connection capacity. |
| Reaction at B larger | Loads are closer to support B overall | Check right-side bearing and connection capacity. |
| Nearly equal reactions | Loads are roughly balanced around midspan | Verify load symmetry and support assumptions. |
Frequently Asked Questions
It returns the vertical support reactions at supports A and B for a simply supported beam under point loads.
Yes. This version supports up to ten separate point loads with independent positions.
Yes. Use one force unit and one length unit consistently across the whole calculation.
Note: This calculator assumes a simply supported beam with point loads only. Continuous beams, distributed loads, uplift, and frame action require a different analysis.
References
Last reviewed: March 14, 2026