How to Calculate Gravel: Volume, Yards & Tonnes

For a rectangular layer: Volume = length × width × depth Convert depth before multiplying. For example, 3 inches is 0.25 ft. A 40 ft × 10 ft driveway at 3 inches has 40 × 10 × 0.25 = 100 ft³ of geometric volume. Divide by 27 to get about 3.70 yd³ before any allowance.

Weight = volume × bulk density. Use supplier density for the named gravel in its expected loose or compacted and moisture condition. “Gravel” can mean pea gravel, river rock, crushed stone, or a graded road-base blend, and their bulk densities differ. A calculator preset is a planning assumption, not a material certificate.

A finished compacted volume may require more loose delivered volume because particles rearrange under compaction. The relationship depends on gradation, moisture, equipment, and target density. Ask the supplier or contractor for a conversion appropriate to the product. Do not automatically apply both a loose-to-compacted factor and a density assumption that already represents the conversion.

If supplier guidance converts the 3.70 yd³ geometric need to 4.15 yd³ loose delivery and the site plan justifies a further small allowance for uneven grade, document each step rather than hiding both in one percentage. Round according to bag size, bulk increment, or truck policy. Verify access and axle/load limits before arranging a bulk delivery.

Driveway quantity depends on excavated grade, edge restraint, base and surface layers, drainage, and compaction. Landscaping beds may use decorative gravel at a different depth and often need geotextile or edging decisions. Separate soil excavation from imported gravel. The Sand, Topsoil, Mulch, and Paver calculators support adjacent landscape quantities.

Enter the measured rectangular dimensions and depth, then select the closest supported gravel type. Review cubic metres, tonnes, and the tool’s indicative load count. Because its density presets and truck capacity are generic, replace them with a supplier quotation when ordering.