Uniformly Loaded Simple Beam
First,is the beam strong enough that it doesn't fail by the fibers on the bottom being torn apart, a fiber failure.
Second, is the beam stiff enough that there will not be excessive deflection. A bouncy floor, cracked tile or plaster would be examples of this.
Third, is the beam strong enough that its fibers don't slip past one another, bend a magazine and watch the pages slide past one another. This is a horizontal shear failure.
This calculator is for timbers 5x5 and larger and differentiates them as "Beams and Stringers" or "Posts and Timbers"
"Beams and Stringers" are 2" or more greater in depth than width.
Under "Total Load" enter 2300
Under "Dead Load" enter 400
Under "Span" enter 144
Under "Width" enter 5.5
Under "Depth" enter 7.5
Under "Species" click Douglas Fir #2 B+S
Click "Show Result"
It should pass in all 3 catagories.
Change the total load to 2400, Bending and Deflection should fail.
Set Total Load back to 2300 and change Dead Load to 300, Deflection only should fail.
Set Total load to 9300 lbs and span to 36", Shear only should fail
User accepts ALL responsibility for their use of this calculator.