Gravel Calculator

The short answer

Volume is length times width times depth. A 10 by 10 foot area at 3 inches deep is 25 cubic feet, or about 0.93 cubic yards — order one yard. One cubic yard covers roughly 100 square feet at 3 inches of depth, and gravel weighs around 1.4 tons per yard, so a yard is roughly 2,800 pounds.

What it depends on

Compacted depth is less than loose depth, so buying to the loose volume under-delivers; 10 to 15% extra covers it. Depth itself depends on use — a walking path needs less than a driveway base, and a driveway base needs compaction in layers rather than one deep pour. Access for delivery is the practical constraint: a full yard weighs more than most cars and needs a truck with somewhere to put it.

Where this stops being useful

This is a volume and weight conversion. It does not cover base preparation, geotextile, edging restraint or drainage, and gravel type and grading vary by region and by supplier. A supplier can quote against the area and depth you describe. General information and planning only, not engineering, structural or code advice.

Gravel is sold by the ton as well as by the cubic yard, and the two are only interchangeable if you know the density. Decorative stone is lighter per yard than compacted road base, so the same volume weighs different amounts of money. Depth is the other variable, and the same depth means different outcomes depending on the job: a driveway needs a compacted base, while a path can be shallower. A four-inch driveway layer over a compacted sub-base will not stay four inches, because it settles.

Groundworks quantities are worth confirming before ordering because they are almost impossible to judge accurately by eye. An eyeballed depth of four inches on a large area can easily be thirty percent out in either direction.

Gravel needs a base and, in many cases, a geotextile membrane underneath to stop the material mixing with the soil below. Without it the stone disappears into the ground over a few years and you end up topping up annually. Order slightly more than the minimum so you have spare for ruts and for levelling off after compaction. Check the delivery method against the quantity — a large order may attract a minimum delivery charge, and picking up in sacks is often cheaper below a couple of tons.

Gravel is priced by weight or by volume depending on the supplier, and the two are linked by density, which is where estimates go wrong. A cubic yard of gravel weighs a ton and a half or more, so a driveway that needs eight cubic yards arrives as well over ten tonnes. Understanding that relationship prevents the awkward discovery that a delivery is heavier, and sometimes larger, than expected. Depth is the design decision. A decorative bed of rounded pebbles might be two inches deep over a membrane. A garden path wants two to three inches. A driveway that has to carry vehicles needs a properly built base — often four to six inches of compacted sub-base beneath a finer surface layer — and skimping on depth is the usual cause of ruts and potholes within a season. The larger and sharper the stone, the better it interlocks and resists movement under wheels. Shape and access matter as much as volume. A long, narrow drive is easy to estimate but may need a wider entrance. An awkward corner needs more stone because the depth cannot be spread evenly. Delivery access is the constraint people forget: a tipper needs somewhere to tip, and if it cannot reach the site, the stone has to be barrowed, which is slow and hard work in tonnage. This calculator gives volume in cubic feet, cubic yards and cubic metres, and weight in tons using a density you can adjust for the type of stone. It assumes an even depth over the measured area and does not include the sub-base layer unless you run it separately. Order slightly more than the calculation suggests, since gravel settles and compacts.

This calculator returns estimates for planning and general information only. It is not engineering, architectural, structural, electrical or code advice, and it cannot replace a qualified professional who has seen the site. Material quantities depend on the actual dimensions, the product you buy and local building codes, so confirm the figures before ordering materials or starting work, and always follow local regulations.