Work out bending moment instantly with clear inputs, formula shown and shareable results.
Maximum bending moment depends on how the load is arranged. A central point load gives PL/4, a uniformly distributed total load gives WL/8, and a cantilever tip load gives PL - four times the simply supported point case for the same load and length. 12 kN centrally on 6 m gives 18 kN m at mid-span.
Central point load
M = P L / 4
Uniform load
M = W L / 8
Cantilever tip load
M = P L
The whole load acts at full lever arm from the single support, with no second reaction to share it. That is four times the simply supported point-load moment.
Divide by the section modulus: sigma = M/Z. That is the pairing that sizes a beam.