Gravel Calculator for Blue Metal & Crushed Rock
Estimate gravel, blue metal or decorative pebble volume for your project. See cubic metres first, plus indicative weight and ordering equivalents.
Calculate Your Gravel
Editable presets only — confirm the required depth for your project
Total Volume
Volume: Length × Width × Depth (converted to metres). For circles: π × radius² × depth. For triangles: ½ × base × height × depth.
Weight: Volume × the selected indicative density. Confirm the exact product conversion with the supplier; see Methodology & Sources.
20 kg equivalent: Estimated kilograms ÷ 20, rounded up. This is a mass comparison, not a retail pack count.
1 m³ bulk-bag equivalent: Volume ÷ 1.0, rounded up. Confirm the supplier's actual bulk-bag size.
Calculate Gravel in Cubic Metres
Measure the area, enter the required depth and select the closest gravel product. LandscapeCalc calculates geometric volume first; it does not add a hidden compaction or waste allowance.
Break Irregular Areas Into Simple Shapes
Calculate rectangles, circles and triangles separately, then add their cubic-metre results. For an area with a cut-out, calculate the full shape and subtract the cut-out volume.
Weight Is an Indicative Conversion
Blue metal, river pebbles and crushed products differ in particle size, fines and moisture. Selecting a subtype changes the planning coefficient used for tonnes, not the volume calculation. Ask the supplier for the conversion applicable to the exact product.
Product and Depth Remain Project Decisions
The calculator does not determine whether a gravel is suitable for a driveway, path, drainage layer or structural application. Use the depth and material specified by the relevant supplier, designer or installer. See the Methodology & Sources page for formulas and limitations.
Gravel Weight Reference
See how the indicative conversion works for a one-cubic-metre starting volume.