Work out hardcore quantity instantly with clear inputs, formula shown and shareable results.
Hardcore is placed and compacted in layers, and broken stone or crushed concrete loses roughly a fifth to a quarter of its loose volume when compacted. Dividing the job into compacted volume first, then applying the loose-to-compacted factor, keeps the order quantity honest.
Loose volume
m³ loose = area x compacted thickness x compaction factor
Tonnage
Tonnes = loose m³ x bulk density / 1000
m³ loose = area x compacted thickness x compaction factor. Hardcore is placed and compacted in layers, and broken stone or crushed concrete loses roughly a fifth to a quarter of its loose volume when compacted.
Usually 150-225 mm compacted per layer with a vibrating roller. Thicker lifts leave the bottom of the layer uncompacted, which shows up later as settlement.
This calculator takes 4 inputs: Area of hardcore, Compacted thickness, Loose to compacted factor, Bulk density. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.