Beam Sizing Calculator
Calculate the required section modulus and suggest a steel beam size for a simply supported beam under uniform load.
How to Use the Beam Sizing Calculator
- Enter the beam span in metres.
- Enter the uniform load in kN/m.
- Select the steel grade.
- Click Calculate to see required section modulus and suggested beam size.
Use Cases
- •Preliminary sizing of steel floor beams.
- •Comparing beam options for roof framing.
- •Checking capacity of existing structural steel.
- •Educational structural steel design.
Formula
M = w×L²/8. Required S = M / Fb. Beam size is selected from standard W-shape table.
Frequently Asked Questions
What is section modulus?
Section modulus S = I/c relates the beam's cross-section geometry to its bending resistance. Higher S means more bending capacity.
What steel grades are available?
A36 has Fy = 250 MPa; A992 (common for W-shapes) has Fy = 345 MPa, allowing smaller beam sections.
Is it free?
Yes, all calculators on OhMyCalc are completely free.