About the Bending Moment Calculator
Bending moment at any point along a simply supported beam, with the bending stress it produces.
Also known as: moment calculator beam, bending moment formula, moment diagram, section modulus stress.
How to use this calculator
- Enter span, distributed load, distance from the left support, section modulus (optional).
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
M(x) = Rx − wx²/2 · σ = M / Z
Worked example
Using the values pre-filled in the calculator above:
- Span = 6 m
- Distributed load = 12 kN/m
- Distance from the left support = 2 m
- Section modulus (optional) = 500 cm³
the calculator returns:
- Moment at 2 m: 48 kN·m
- Maximum moment (mid-span): 54 kN·m
- Shear at that point: 12 kN
- Support reactions: 36 kN each