Work out concrete beam volume instantly with clear inputs, formula shown and shareable results.
Beam concrete is the section area times the span, repeated for each beam. Formwork covers the soffit and both sides, so the developed width is the beam width plus twice its depth. Reinforced concrete weighs about 2.4 tonnes per cubic metre, which sets the load the falsework must carry.
Beam volume
V = width x depth x length x count
Formwork
Area = (width + 2 x depth) x length x count
V = width x depth x length x count. Beam concrete is the section area times the span, repeated for each beam.
Beam depth is usually quoted overall. If the slab is cast monolithically, deduct the slab thickness from the beam depth for the concrete take-off so the volume is not counted twice.
This calculator takes 4 inputs: Beam width, Beam depth, Beam length, Number of beams. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.