Beam Load Capacity Calculator

Inputs

Load case

Support and loading case used for maximum bending moment.

Span length (L)

Clear span or cantilever length for the selected case.

Section modulus (S)

Elastic section modulus about the bending axis.

cm³

Allowable bending stress (sigma_allow)

Material allowable or design bending stress before applying the safety factor.

MPa

Safety factor (N)

Design stress = allowable stress / safety factor.

Applied load to check (F or W)

Total point load or total uniform load to compare against the allowable load.

Default result

Allowable total load(F_allow)

8,000N

Pass

8 kN · 1,798 lbf

Derived from M_allow = (allowable stress / safety factor) * S.

Load that reaches design bending stress.

Also computed

Applied utilization(U)0.25

Applied bending stress(sigma)25MPa

Required section modulus(S_req)5cm³

Allowable moment(M_allow)2,000N·m

Applied moment(M)500N·m

Allowable load / span(w_eq)8N/mm

Method notes 3 notes

This is an elastic bending-stress capacity check using sigma = M/S. It does not check deflection, shear, bearing, web crippling, local buckling or lateral-torsional buckling.
Uniform-load cases use total load W across the span. The load/span output is the equivalent uniform line load for quick comparison.
Use the section modulus about the actual bending axis and apply code-specific resistance factors where required.