Combined Bending and Axial Loading
A member that has a load applied both in bending as in a beam,and axially as in a column is sized according to the formulas used in this calculator. First the maximum allowable load as a column is checked, then the maximum allowable load as a beam. When a column is axially loaded and a load pushes on the side, a reduction in the allowable axial load must be made. There is an interrelation, as the axial load increases towards the maximum allowed column load, the member is less able to take side loading. As the axial load decreases the member can accept more side load. Think of a popsicle stick between thumb and forefinger. As you squeeze together this loads the column along its axis. If you push on the middle of the stick it is easier to buckle the stick the harder it has been loaded axially.

This calculator uses math formulas from the 1944 NDS section 401-403 "Combined Bending and Axial Loading"
No representation is made as to whether they are correct or that they are correct for your situation.
This calculator is not for design, it is out of date, the math is fairly simple and it is for educational use only.
The user assumes all risk from their use of this program.