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Excavation & spoil volume

Estimate in-situ excavation and loose spoil using an entered bulking factor.

Quantity / scenario planning · Reviewed 7 October 2026

Your inputs

Check all starting values against your project and product. Enter your own prices; keep costs on the same GST basis.

MEASURE FIRST

How to prepare your inputs

Use measured excavation dimensions and a contractor-confirmed bulking factor. Loose spoil volume differs from in-situ ground volume.

How this calculation works

In-situ volume = length × width × depth. Loose spoil = in-situ volume × bulking factor. Loads round up by volume capacity.

Worked example

6 × 4 × 0.5 m is 12 m³ in situ. Factor 1.2 gives 14.4 m³ loose spoil and three 5 m³ loads.

Assumptions & exclusions

Bulking factor is illustrative and soil dependent. Volume loads do not establish legal payload: mass may control. Excludes contamination, underground services, shoring and excavation safety assessment.

Your next step

Check service locations, ground conditions, contamination, excavation support and legal transport payload with your contractor.

Further reading

  • ANL material weights and volumes

These resources provide background information. Confirm current product specifications and project requirements with your supplier or trade professional.

What if my shape or product is different?

Use dimensions and product data that match the stated method. For complex work, calculate separate sections or obtain a project-specific take-off. Do not apply simple geometry to structural or compliance decisions.

Why are quantities rounded up?

Whole bags, packs, sheets or cartridges round up to purchasable units. Decimal area or volume results are planning figures; confirm order increments with the supplier.

Are my entries saved?

No. Entries remain in the current browser page and clear on reload. Printing can save your results and inputs as a PDF on your device.

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