Excavation Volume
Calculator

Volume equals the area to be excavated multiplied by the average depth — length × width × depth for a rectangular footing or basement, given in cubic yards or cubic metres depending on convention. More complex shapes (sloped sides, trenches) need adjusted formulas.

Soil expands when it's dug up and loosened — undisturbed (bank) soil becomes bulkier once excavated, typically by 15-30% depending on soil type, so the volume of spoil to be hauled away is larger than the in-ground volume that was removed.

Bank volume is the volume of undisturbed soil in place before digging (what the excavation calculation directly measures), while loose volume is the larger volume that same soil occupies after excavation due to the air gaps introduced by loosening — haul truck capacity should be planned around loose volume, not bank volume.

A basic rectangular calculation doesn't include battered (angled) sides, which are often required by code for deeper excavations to prevent collapse — for a sloped-side trench or pit, the volume calculation needs to average the wider top opening with the narrower bottom, increasing the total volume beyond a simple rectangular prism estimate.

Bank volume tells you how much material physically needs to be removed from the ground (informing dig time and equipment sizing), while loose volume tells you how many truckloads or how much disposal capacity you'll need, since haul trucks and dump fees are based on the bulked-up volume, not the original in-ground measurement.