Uniformly Loaded Simple Beam

When specifying a beam or joist three things are usually considered;
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.
The calculator was created using Javascript on a Windows browser using standard engineering formulas. Please check compatability on your browser by performing the following check.
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.

Click Here For Info on How the Calculator Works

Total Load on Beam(pounds)
Dead Load on Beam (pounds)
Span of Beam (inches)
Width of Beam
Depth of Beam
Select Species and Grade
Allowable Fiberstress in Bending (Fb)(psi)
Modulus of Elasticity (E or MOE)(million psi)
Allowable Shear (Fv)(psi)
Click Here For Wood Design Values

Fiberstress in BendingDeflection Horizontal shear
Max Moment (ft-lbs) Deflection (inches) Shear (PSI)
Section Modulus Required Max 1/360 (Floor) Section Required
Section Modulus Input Max 1/240 (Roof) Section Input
Section Modulus Pass/Fail Deflection Pass/Fail Shear Pass/Fail
Minimum Bearing Each End (sq") Maximum Compression Perpendicular to Grain (psi)
These calculators are math formulas from engineering texts written into Javascript. This is based on the '01 NDS, the method has changed with the '05 edition. No representation is made as to whether they are correct or that they are correct for your situation. They are for educational use only. The user assumes all risk from their use of this program.