Uniform Load Calculator

Calculate total distributed load, support reactions, maximum shear, maximum bending moment, and deflection for a simple beam with a uniform load. Use this uniform load calculator for beams, joists, rafters, girders, headers, floor loads, roof loads, and preliminary structural planning.

Calculate Uniform Load

Simple beam uniform load formulas: total load = wL, reaction = wL ÷ 2, maximum moment = wL² ÷ 8, deflection = 5wL⁴ ÷ 384EI.
Your result will appear here.

How the uniform load calculator works

Total load:
The calculator multiplies the uniform line load by the beam span to estimate total distributed load.

Support reactions:
For a simple-span beam with a full-span uniform load, the calculator divides the total load evenly between supports.

Maximum moment:
The calculator estimates the maximum bending moment at midspan using wL² ÷ 8.

Deflection check:
The calculator estimates midspan deflection and compares it to the selected span limit.

Why use a uniform load calculator?

A uniform load calculator helps estimate how an evenly distributed load affects a beam, joist, rafter, header, girder, or support.

It can help compare total load, line load, reactions, shear, bending moment, deflection, span ratio, and area-load conversions.

What your result means

Your result shows estimated line load, total uniform load, support reactions, maximum shear, maximum bending moment, deflection, allowable deflection, and span ratio. These are simplified planning estimates only.

Uniform load formulas

Frequently asked questions

What is a uniform load?

A uniform load is a load spread evenly along a beam or member, such as floor load on a joist, roof load on a rafter, or wall load on a beam.

How do you calculate total uniform load?

Multiply the line load by the span. For example, 400 PLF over 12 feet equals 4,800 pounds of total load.

How do you convert PSF to PLF?

Multiply pounds per square foot by tributary width in feet. For example, 55 PSF over an 8-foot tributary width equals 440 PLF.

Where is maximum moment for a uniform load?

For a simple-span beam with a full-span uniform load, maximum moment occurs at midspan.