Beam Load Calculator

Calculate maximum shear, bending moment, and deflection for simply supported and cantilever beams under uniform or point loads.

Inputs

Load Type

Load Magnitude

lb or lb/ft

Span Length

Support Type

Tab to move between fields

Results

Maximum Shear

5,000 lb

≈ 5 grand pianos

Maximum Bending Moment

25,000 ft·lb

Maximum Deflection0.62 in

How to Use This Calculator

Select load type (uniform distributed load or point load at center).
Enter load magnitude and span length.
Choose support type (simply supported or cantilever).
Review maximum moment, shear, and deflection results for structural sizing.

How the result changes with Load Magnitude

Load Magnitude	Maximum Shear	Maximum Bending Moment
100,000	1,000,000 lb	5,000,000 ft·lb
350,000	3,500,000 lb	17,500,000 ft·lb
650,000	6,500,000 lb	32,500,000 ft·lb
900,000	9,000,000 lb	45,000,000 ft·lb

What each input means

Load Type: Select whether the beam carries a distributed uniform load or a single concentrated point load at midspan.
Load Magnitude: For uniform load enter lb/ft; for point load enter total lb.
Span Length: Clear span length of the beam between supports.
Support Type: Simply supported has pins at both ends; cantilever is fixed at one end and free at the other.
Elastic Modulus (E): Modulus of elasticity of the beam material per AISC 360 and NDS. Steel: 29,000 ksi; aluminum: 10,000 ksi; Douglas fir: 1,600 ksi; LVL: 1,900 ksi.
Moment of Inertia (I): Second moment of area of the beam cross-section per AISC Steel Construction Manual. W8×31: I=110 in⁴; W12×50: I=394 in⁴; W16×67: I=954 in⁴. For wood joists, calculate bh³/12.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Load Type = 1, Load Magnitude = 500, Span Length = 20, Support Type = 1 = 6 input(s) provided
Calculate Maximum Shear
Maximum Shear
5000 = 5000
Calculate Maximum Bending Moment
Maximum Bending Moment
25000 = 25000
Calculate Maximum Deflection
Maximum Deflection = abs(maxDeflection)
0.6207 = 0.6207

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