Beam Load Calculator
Calculate the maximum load capacity of a beam based on span, load type, and material.
Useful for structural planning and engineering estimates.
Maximum Load Capacity
Beam load capacity depends on span length, material properties, cross-section dimensions, and load distribution type.
For a rectangular beam under uniform load:
Max Load (lbs) = (8 x Fb x S) / (L x 12)
Where:
Fb= allowable bending stress (psi or MPa)S= section modulus =(b x d²) / 6(b = width, d = depth)L= span length
For a point load at center:
Max Load (lbs) = (4 x Fb x S) / (L x 12)
Imperial units: Stress in psi, dimensions in inches, span in feet Metric units: Stress in MPa, dimensions in mm, span in meters
Common allowable bending stress (Fb) values:
- Douglas Fir (No. 2): 875 psi (6.0 MPa)
- Southern Pine (No. 2): 1,000 psi (6.9 MPa)
- Steel (A36): 22,000 psi (152 MPa)
- LVL (Laminated Veneer Lumber): 2,600 psi (17.9 MPa)
Important: This is a simplified calculation for preliminary estimates. Always consult a licensed structural engineer for actual building design.