Beam Load Calculator
Bending moment and deflection for a beam.
Enter your values
ⓘ Live results
Results
- Max bending moment
- 14.06 kNm
- Max shear
- 11.25 kN
- Max deflection
- 2.15 mm
- Span/deflection ratio
- L/2,321
Quick answer
A simply supported beam under uniform load has maximum moment at midspan equal to wL²/8.
M = wL² ÷ 8
How to use the Beam Load Calculator
- 1Enter the uniform load per metre.
- 2Enter the clear span.
- 3Enter the beam's E and I values from the section table.
Worked example
Using the values the calculator loads with:
Inputs
- Uniform load4.5 kN/m
- Span5 m
- Young's modulus200 GPa
- Second moment of area8500 cm⁴
Results
- Max bending moment14.06 kNm
- Max shear11.25 kN
- Max deflection2.15 mm
- Span/deflection ratioL/2,321
Frequently asked questions
What deflection is acceptable?
L/250 for general use, L/360 under plaster ceilings.
Is this a design tool?
It is an estimate — structural work needs a qualified engineer.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.