How to Calculate How Much Gravel You Need
I built this gravel calculator to help you figure out the volume and weight of gravel needed before ordering from a landscape supplier. The basic calculation multiplies length × width × depth to get the volume in cubic feet or cubic metres, then converts to tons or cubic yards based on the gravel type. Getting this right matters because gravel is heavy and expensive to return — a single cubic yard weighs roughly 2,700 to 3,000 pounds (1.35 to 1.5 tonnes) depending on stone type.
Depth is the variable most people underestimate. For a decorative garden path, 2 inches of gravel looks good and functions well. For a driveway that needs to support vehicle weight, you need at least 4 inches of base gravel compacted, plus 2 inches of surface gravel — so 6 inches total. Skimping on depth leads to ruts, mud, and the miserable experience of digging out a stuck vehicle.
Common Gravel Types and Their Best Uses
Not all gravel is suitable for every application. Here's a quick guide to matching stone type to project:
- Crushed stone (#57 or #3): the most common driveway base material — angular edges lock together and compact well.
- Pea gravel: smooth, rounded pebbles ideal for garden paths, playgrounds, and dog runs; not suitable for driveways as it shifts underfoot and under tyres.
- Decomposed granite (DG): fine-grained and compacts almost like soil; excellent for paths, patios, and xeriscaping.
- River rock: decorative and good for drainage applications like French drains and dry creek beds.
Ordering and Delivery Tips
Most landscape suppliers sell gravel by the cubic yard or the tonne, and they'll convert between the two for you if you tell them the stone type. Ordering in bulk (delivered by truck) is significantly cheaper per unit than buying bags from a home improvement store — typically 50–70% cheaper per ton. For jobs requiring more than 2–3 cubic yards (about 8–10 standard bags each), bulk delivery almost always makes financial sense.
When the delivery truck arrives, have a clear plan for where the pile will go. Gravel trucks dump from the back, so you need clearance for the truck to back in and enough space for the pile. Spread the gravel as soon as possible — a large pile left on grass kills the turf within a few days, and fresh gravel is much easier to spread than gravel that has settled and compacted.
Frequently Asked Questions
How deep should gravel be for a driveway?
For a residential driveway, the standard recommendation is a 4-inch layer of compacted base material (coarse crushed stone or road base) topped with a 2-inch surface layer of smaller decorative gravel — 6 inches total. In areas with soft or clay-heavy soil, increase the base to 6 inches and consider a geotextile fabric underneath to prevent the gravel from sinking into the subgrade over time.
How many square feet does a cubic yard of gravel cover?
One cubic yard covers 324 square feet at 1 inch deep, 162 square feet at 2 inches deep, 108 square feet at 3 inches deep, and 81 square feet at 4 inches deep. For quick mental maths: divide 324 by your intended depth in inches to get the coverage area per cubic yard. This is a rough guide — gravel compacts 10–15% when spread, so your coverage will be slightly more than the theoretical calculation.
Do I need landscape fabric under gravel?
For decorative garden beds and paths, landscape fabric under gravel helps suppress weeds and prevent gravel from mixing into the soil over time. Use a heavy-duty woven geotextile fabric rather than thin black plastic — plastic tears quickly and blocks water and air. For driveways, a geotextile separator fabric between the subgrade and base gravel improves longevity significantly in areas with soft or expansive clay soils.