Stockpile Volume Calculator
Estimate the cubic yards and tons in a conical pile of gravel, sand, mulch, or dirt from its base diameter and height. For yard inventory and delivery checks.
How this calculator works
Loose material dumped in a pile forms a cone. The calculator computes the cone’s volume from base diameter and height, converts to cubic yards, and applies your material density to estimate tons.
Formula: Cubic feet = ⅓ × π × (base diameter ÷ 2)² × height. Cubic yards = ÷ 27. Tons = cubic yards × density.
Worked example
A gravel pile 20 feet across the base, 8 feet tall, density 1.4 tons/yd³:
- Radius: 10 ft
- Cubic feet: ⅓ × π × 10² × 8 ≈ 838 ft³
- Cubic yards: 838 ÷ 27 ≈ 31.03 yd³
- Tons: 31.03 × 1.4 ≈ 43.44 tons
Reference (gravel cone, 1.4 t/yd³)
| Base × height | Cubic yards | Tons |
|---|---|---|
| 10 ft × 5 ft | 4.85 | 6.8 |
| 20 ft × 8 ft | 31.03 | 43.4 |
| 30 ft × 12 ft | 104.7 | 146.6 |
How to measure
Measure the base diameter at the widest point and estimate the height to the peak. Set the density to match your material. The result is loose volume — compacted material occupies less.
Frequently asked questions
How do you estimate the volume of a pile?
A dumped pile of loose material forms a cone. Its volume is one-third of pi times the base radius squared times the height. The calculator converts that to cubic yards and, using the material's density, to tons.
How do I measure a pile I can't climb?
Measure the base diameter by walking a tape across the widest point, and estimate the height by sighting the peak against a known reference or measuring with a long pole. Even rough measurements give a useful inventory estimate.
What density should I use?
Gravel and river rock are about 1.4 tons per cubic yard, sand and crushed stone about 1.35, topsoil about 1.1, and mulch far less. The calculator defaults to gravel; adjust the density for your material — see the Methodology page for the full table.
Why doesn't my pile match the delivered tons?
Loose piled material has air gaps, so a cone estimate reflects loose volume, not compacted. A pile also isn't a perfect cone — a flat-topped or elongated pile holds more than the formula suggests. Treat the result as an approximate inventory figure.
Can I use this for mulch or wood chips?
Yes, for the volume in cubic yards. For tons, mulch and chips are much lighter than aggregate, so lower the density well below 1 — most landscape suppliers sell them by the cubic yard rather than by weight.
Estimates only. Verify quantities with your supplier before purchasing.