How the gravel estimate works
Gravel coverage is a volume problem dressed up as an area problem. You know the surface you want to cover and how deep you want the layer, so the calculator multiplies the area by the depth (converted from inches to feet) to get cubic feet, then divides by 27 to express it in cubic yards — the unit most landscape suppliers quote.
Gravel is frequently sold by weight rather than volume, so the cubic-yard figure is multiplied by a density to estimate tonnage. Crushed stone runs around 1.4 tons per cubic yard, but pea gravel, river rock, and screenings each weigh differently, so adjust the density field if your supplier lists a specific value.
Choosing the right depth
Depth is the input that most affects how much you buy, and it depends entirely on the job. Going an inch deeper than necessary across a large area can add a surprising number of tons to the order.
- Decorative beds and garden paths: 2 to 3 inches.
- Walkways and patios: 3 to 4 inches over a compacted base.
- Driveway base layers: 4 to 6 inches, often built up in compacted lifts.
- For driveways, plan separate layers — a coarse base topped with a finer surface gravel.
Tips for an accurate order
Measure the area carefully and break irregular shapes into rectangles or circles you can calculate separately. Gravel compacts as it settles and is driven on, so loose-delivered volume shrinks once in place.
Confirm the density with your supplier rather than relying on the default, and ask whether the price is per ton or per cubic yard so you compare quotes on the same basis. Adding a small margin avoids a second delivery fee for a few missing bags.
What this estimate leaves out
This tool sizes the gravel itself. It does not include the geotextile fabric, edging, or compacted sub-base that a durable driveway or patio usually needs, and it does not account for compaction loss, which can add several percent to the required volume. Treat the result as a starting quantity and round up.
Formula
volume(yd³) = area(ft²) × (depth(in)/12) / 27; weight(tons) = volume × densityFrequently asked questions
- How deep should a gravel driveway be?
- A driveway base is usually 4–6 inches deep; decorative or walkway gravel is often 2–3 inches.