Stone Calculator

What this calculator does

Estimates tonnes and volume of landscaping stone for a bed or path from area and depth.

How to use it

1. Enter width and length.
2. Enter depth in centimeters.
3. Set waste and read tonnes and cubic meters.

Formula

baseVolume = Width × Length × Depth/100
metric tonnes = baseVolume × 1.5 × (1 + Waste Margin (%) / 100)
Material volume m³ = baseVolume × (1 + Waste Margin (%) / 100)

Formulas are shown in metric units, exactly as the calculator computes them. Imperial entries are converted to metric first. Waste is applied as a multiplier (1 + waste/100).

Areas are in m² and volumes in m³. Centimeters are divided by 100 to give meters.

Variables

Worked example

Using the default values of this calculator (Width = 5 m, Length = 10 m, Depth = 5 cm, Waste Margin (%) = 10 %), the calculator returns:

baseVolume = 5 × 10 × 5/100
metric tonnes = baseVolume × 1.5 × (1 + 10 / 100)
Material volume m³ = baseVolume × (1 + 10 / 100)

• Stone Needed: 4.125 t
• Material volume: 2.75 m³

Assumptions and limitations

• Weight uses a 1.5 t/m³ bulk density copied from the sand assumption; stone varies a lot, so treat the tonnage as rough.
• Volume is more reliable than tonnes here.

Waste, rounding and buying

Ask your supplier for the stone bulk density and convert from the volume result. Round up.

Frequently asked questions

Is the density right for my stone?

Probably not exactly. Use the volume result and the supplier density.

Do I need extra?

Settling and irregular ground are typical, so keep the waste margin.

Related calculators

• Gravel Calculator
• Sand Calculator
• Paver Calculator