Structural

Beam Load Calculator

Calculate simple beam deflection, stress, and load for common configurations.

Input Parameters

Units:

Support Type

Load Type

Beam Length

Point Load

lbf

Beam Profile

Moment of Inertia (I)

in⁴

Distance to Neutral Axis (c)

Results

Enter beam parameters and click Calculate

What is a Beam Load Calculator?

A beam load calculator determines deflection, bending stress, and support reactions for structural beams under various loading conditions.

These calculations are essential for ensuring beams can safely support applied loads without excessive deflection or stress that could lead to failure.

How to Use

Select the support type (simply supported, cantilever, or fixed)
Choose the load type (point load or distributed)
Enter beam length and applied load
Select a standard beam profile or enter custom section properties
Click Calculate to see deflection, stress, and reactions

FAQs

Moment of inertia (I) measures a beam's resistance to bending. A higher I means less deflection under load. It depends on cross-sectional shape - I-beams have high I because material is concentrated far from the neutral axis where it's most effective.

Simply supported beams rest on supports that allow rotation (like a board on two sawhorses). Fixed ends are rigidly connected, preventing rotation. Fixed beams have less deflection and moment at center, but higher moments at the fixed supports.

Common limits are L/360 for floors supporting brittle finishes, L/240 for roof members, and L/180 for members not supporting finishes. Critical applications may need tighter limits. These are span (L) divided by a factor - smaller deflection = larger divisor.

The neutral axis is the line through a beam's cross-section where there is zero stress during bending. Material above is in compression, below is in tension. For symmetric shapes like W-beams, it's at the geometric center. Stress increases linearly with distance from the neutral axis.

Standard profiles (W-shapes, channels, HSS) have published section properties. Using standard shapes simplifies design, ensures availability, and allows direct lookup of I and S values. The calculator includes common sizes but you can enter custom values for any cross-section.

Limitations

• Assumes linear elastic material behavior (small deflections)
• Does not check shear stress or lateral-torsional buckling
• Point loads assumed at center; off-center loads need different formulas
• Not suitable for continuous spans or complex loading
• Critical structures require professional engineering review