Wood Beam Design for Construction: An easy to use wood beam design calculator for construction & building. Inputs: span, beam size, lumber type and option of point load or uniformly distributed load (only simple beam spans included). Outputs: calculated stress in bending, the allowable stress of your beam type and the calculated and allowed deflection. ConstructionKnowledge. net: These apps our part of our mission at ConstructionKnowledge. net to help those in construction to learn and rise in this crazy world of construction. Please send us your ideas for apps, suggestions for new web content and follow our blog. It's Ned's fun and informative take on the construction industry.