Shear Force Calculator Formula

Understand the math behind the shear force calculator. Each variable explained with a worked example.

Formulas Used

Each Reaction

reaction = total_load / 2

Max Shear Force

max_shear = total_load / 2

Total Load

total_load_out = total_load

Variables

VariableDescriptionDefault
spanBeam Span(ft)16
load_plfUniform Load(lb/ft)300
total_loadDerived value= span * load_plfcalculated

How It Works

Shear Force (Simply Supported Beam)

V_max = wL / 2

For a simply supported beam with uniform load, the maximum shear force occurs at the supports and equals half the total load. The shear force decreases linearly to zero at mid-span.

Worked Example

16 ft beam with 300 lb/ft uniform load.

span = 16load_plf = 300
  1. 01Total load = 16 x 300 = 4,800 lbs
  2. 02Reaction at each support = 4800 / 2 = 2,400 lbs
  3. 03Max shear = 2,400 lbs (at each support)

Ready to run the numbers?

Open Shear Force Calculator