Work out earthwork volume (average end area) instantly with clear inputs, formula shown and shareable results.
Average end areas multiplies the mean of two cross-sections by the distance between them, which is quick and is the method most contracts specify for payment. The prismoidal formula uses the mid section as well, L/6 x (A1 + 4Am + A2), and is more accurate wherever the section changes non-linearly along the chainage.
Average end areas
V = (A1 + A2) / 2 x L
Prismoidal
V = L/6 x (A1 + 4 Am + A2)
V = (A1 + A2) / 2 x L. Average end areas multiplies the mean of two cross-sections by the distance between them, which is quick and is the method most contracts specify for payment.
Because it is simpler, reproducible and does not require mid sections to be surveyed. The bias is systematic and is absorbed into the tendered rate.
This calculator takes 4 inputs: Area at the first section, Area at the mid section, Area at the second section, Distance between the end sections. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.