How to Calculate Gravel for a Driveway or Patio
Calculating the amount of gravel, crushed stone, or pea gravel needed for a landscaping project involves finding the total cubic volume of the area and converting it into tons. While some suppliers sell mulch and soil by the cubic yard, aggregates and heavy stones are almost universally sold and delivered by the ton.
- L = Area Length (in feet)
- W = Area Width (in feet)
- D = Desired Depth (in inches)
Note: A standard conversion factor for regular crushed stone or gravel is 1.4 tons per cubic yard (approx. 2,800 lbs). Very dense or wet materials may weigh slightly more.
If you are planning to buy bagged gravel from a local home improvement store, note that standard bags typically contain 0.5 cubic feet. Because 1 cubic yard equals 27 cubic feet, it takes roughly 54 bags to equal a single cubic yard.
| Gravel Depth | Coverage Area (Square Feet) | Common Application |
|---|---|---|
| 2 inches | ~115 sq ft | Light pathways and decorative garden beds. |
| 3 inches | ~77 sq ft | Standard patios and heavy foot-traffic areas. |
| 4 inches | ~57 sq ft | Standard residential driveways and parking pads. |
| 6 inches | ~38 sq ft | Heavy vehicle driveways or soft subgrade bases. |
Frequently Asked Questions
How much does a cubic yard of gravel weigh?
A standard cubic yard of dry gravel or crushed stone typically weighs about 2,800 pounds, which is 1.4 tons. Keep in mind that different types of stone have varying densities; for example, volcanic rock (scoria) is much lighter, while smooth river rock can be slightly heavier.
How deep should a gravel driveway be?
For a standard residential driveway, a total depth of 4 to 6 inches is recommended. Often, this is laid in two layers: a base layer of larger, jagged stones (like #3 or #4 crushed stone) to establish a solid foundation, followed by a top layer of smaller gravel (like #57 stone or crusher run) to lock the surface together.
Should I put landscape fabric under my gravel?
Yes. Laying a heavy-duty, woven geotextile fabric beneath your gravel is highly recommended. It serves two primary functions: it prevents weeds from growing up through the stones, and more importantly, it prevents the heavy gravel from slowly sinking into the softer soil or mud beneath over time.