Measure footing concrete
Multiply total footing run by specified footing width and thickness.
Calculate pads and widened sections separately when their dimensions differ.
Measure the trench separately
Excavation width and depth often exceed concrete dimensions for access, forms, working space, or subbase.
Do not use concrete volume as excavation volume.
Read the rebar schedule
Count longitudinal bars, transverse bars, dowels, laps, hooks, and special bars from the design.
Quantity calculations must not invent reinforcement spacing.
Convert to purchase units
Convert concrete to cubic yards, excavated soil to the hauling unit, and rebar to stock lengths or weight as required.
Round each material only at its actual purchase unit.
Check site conditions
Soil, groundwater, frost, bearing, and access can change the work materially.
Confirm the footing design and excavation plan before construction.