Gravel Calculator

Gravel's dual pricing convention — sold by suppliers either by volume (cubic yards or cubic meters) or by weight (tons or tonnes), depending on the specific supplier and region — is exactly why this calculator provides both figures, and understanding why the two aren't interchangeable without a density conversion helps explain a genuinely common point of confusion when ordering aggregate material.

Density — how much a given volume of gravel actually weighs — varies meaningfully across different aggregate types, which is the core reason a single universal volume-to-weight conversion factor doesn't perfectly apply to every gravel product. Crushed stone, with its angular, irregular particle shapes, packs and settles differently than rounded pea gravel, and both differ from other aggregate types like decomposed granite or recycled crushed concrete. This calculator uses a reasonable general estimate (1.6 tonnes per cubic meter) that works well as a starting reference, but confirming your specific chosen product's actual density with the supplier remains the more reliable approach for a large, cost-sensitive order, exactly analogous to the same density-verification advice that applies to asphalt and concrete material estimation.

Beyond simple material budgeting, understanding gravel's structural role — particularly for a driveway base layer, as opposed to a purely decorative garden path topping — matters for choosing an appropriate depth in the first place. A gravel base layer beneath a driveway (whether that driveway's final surface is asphalt, concrete, pavers, or gravel itself) serves a genuine structural, load-bearing function: it provides drainage beneath the surface layer and distributes vehicle weight across a wider area than the surface material alone could manage, both of which directly affect how well the finished driveway resists rutting, cracking, and water damage over its lifetime. This structural role typically calls for a meaningfully deeper base layer than a simple decorative garden path would need, since a garden path's gravel is primarily serving an aesthetic and basic walkability function rather than bearing significant structural load.

Compaction is a further consideration specifically relevant to base-layer applications: gravel delivered and spread loosely occupies more volume than the same material does once properly compacted (typically using mechanical compaction equipment for anything beyond a small area), since compaction works by pressing the individual aggregate particles into a denser arrangement with fewer air gaps between them. This means a target final compacted depth for a structural base layer requires ordering somewhat more loose material than that target depth alone would suggest — a distinct, related consideration to the settling that affects topsoil and mulch over time, though compaction for a gravel base is typically an active, deliberate mechanical process during installation rather than gradual passive settling that continues after the project is complete.