To determine the maximum load a wooden construction beam can safely bear using a wood beam calculator, you need to enter the length of the span, the beam size and the species of lumber. Complex calculators optionally allow for more information to improve the calculations, such as live and dead loads, the structural grade, or whether there is an overhang.
Calculators base their figures on industry standards such as National Design Specification standards released every few years by the American Wood Council. Advanced calculators can also calculate based on the load of least duration and can consider other factors such as shear stress and lateral support. Some of them are capable of accounting for snow, construction or seismic loads.
To get results, enter all available information into the online calculator and click the "calculate" or "update" button. Calculators on American sites accept and calculate figures in inches, feet and pounds. Depending on the type of wood, the nature of the construction and other factors, different-sized beams are required. For example, a span of 10 feet spaced 16 inches apart can bear a uniformly distributed load of 1,167 foot-pounds with 2x10 beams of southern pine. For fir, spruce and hemlock, only 2x8 beams are necessary to bear a matching load.