Calculate beam support reactions from point loads, uniform loads, partial distributed loads, applied moments, and load locations. Use this support reaction calculator for simply supported beams, floor beams, roof beams, deck beams, headers, joists, rafters, and preliminary structural load paths.
Point loads:
The calculator multiplies each point load by its distance from the left support to calculate its moment contribution.
Uniform loads:
A full-span uniform load is converted into one equivalent point load located at midspan.
Partial distributed loads:
A partial load is converted into an equivalent point load acting at the center of its loaded length.
Support reactions:
The calculator solves right reaction from moment equilibrium, then solves left reaction from vertical force equilibrium.
A support reaction calculator helps determine how much vertical load each beam support, wall, post, column, or bearing point receives.
It can help estimate post loads, wall loads, bearing reactions, footing loads, beam end reactions, and load paths before additional structural checks.
Your result shows estimated left support reaction, right support reaction, total downward load, equivalent load locations, moment balance, reaction split, maximum reaction, and total reaction for multiple similar beams. These are simplified static equilibrium estimates only.
A support reaction is the force that a support provides to hold up a beam. For vertical loads, it is usually the upward force at a wall, post, column, or bearing point.
Add all vertical loads, then take moments about one support to find the opposite reaction. The remaining reaction equals total load minus the first reaction.
Reactions are equal only when the loading is symmetrical. If a load is closer to one support, that support carries a larger share of the load.
No. Support reactions are only one part of beam analysis. Final design should also check shear, bending, deflection, bearing, connections, load combinations, material capacity, and local code requirements.