OWL EYE® · Free tool

Stockpile tonnage calculator: volume × density.

Convert a stockpile volume into tonnes — or estimate the volume first from simple pile geometry. Enter a measured volume, a conical pile (V = π·r²·h/3), or a freeform pile (footprint × height × shape factor 0.5–0.7), then pick a bulk density. The result updates live.

1 · Pile volume

Volume (m³)

Base diameter (m)

Height (m)

Cone volume: V = π · r² · h / 3 — a good model for a single free-poured pile.

Footprint area (m²)

Average max height (m)

Shape factor (0.5–0.7)

V ≈ footprint × height × shape factor. Elongated windrows tend toward 0.5; fuller, rounded piles toward 0.7.

2 · Bulk density

Material (loose bulk density, t/m³)

1,600 t 1,000 m³ × 1.60 t/m³

Honest accuracy note: bulk density varies with moisture and compaction by ±10–20 % — so any volume-to-tonnes conversion is only as good as the density figure and the volume behind it. For inventory you can book, continuous LiDAR measurement delivers ±1 % volume accuracy with material-calibrated density: OWL EYE® STOCKPILE · stockpile monitoring systems.

A free tool by Sachtleben Technology — OWL EYE®. Values are indicative estimates, not a measurement.