BEAMS & DEFLECTION

Cantilever Beam Calculator

Calculate fixed-end moment, maximum stress and tip deflection for a rectangular cantilever with an end load.

SI & US customary units Live results Inputs stay in your browser

Input parameters

Illustrative input, not a certified material property.

Values are calculated locally in your browser.

Results

Live calculation
Maximum deflection
3.2 mm

Theoretical result · verify applicability below

Maximum bending stress24 MPa
Maximum bending moment2,000 N·m
Second moment of area4,166,670 mm⁴
Vertical support reaction1,000 N

Engineering model

PLdeflection (exaggerated)

Schematic illustration · not to scale

Formula & method

Mmax = PL · I = bh³/12 · σmax = Mmax(h/2)/I · δtip = PL³/(3EI)

The fixed support resists both the vertical force and its bending moment. Bending stress is greatest at the fixed end while displacement is greatest at the free tip. A perfectly rigid support is assumed, so real connection flexibility adds deflection.

Worked example

P = 1,000 N, L = 2 m, E = 200 GPa, b = 50 mm and h = 100 mm give root moment = 2,000 N·m, bending stress = 24 MPa and tip deflection = 3.2 mm.

The initial inputs reproduce this example. Material values are illustrative inputs, not a material database or certified design values.

Assumptions & limitations

Uniform rectangular section, ideal fixed root, static transverse end load, linear elasticity and small slopes. Excludes shear deformation, self-weight, support compliance, lateral instability and local root stress concentrations.

No factor of safety or design-code allowance is applied unless explicitly stated. Read the engineering disclaimer before applying these results.

Checking your calculation

Confirm the load direction and units first. Check the schematic against your actual supports and geometry, then compare the worked example with your own independent calculation. A valid numerical result does not establish that the model is appropriate for a real component.

For background, consult the Air Force Stress Analysis Manual’s column analysis and MIT’s Mechanics of Materials learning modules. Use applicable design standards and certified material data for real designs.