How the gravel planner works
A real driveway is rarely one rectangle. There is usually a straight run, a wider apron where it meets the street, maybe a parking pad or a turning area, and sometimes a planted island in the middle. This planner lets you enter each of those as its own section, subtract anything that will not be graveled, and then turns the whole project into one order: volume, weight, bags and delivery loads.
Measuring a driveway in sections
- Sketch the layout and mark the straight parts, the flares and any round turning areas.
- Use the simplest shape for each part. A straight run is a rectangle. A flare that widens toward the street is a trapezoid. A turnaround is often a circle or a half circle.
- Measure along the ground in feet or meters, and use the same unit system for the whole project.
- Subtract islands, planters or existing concrete pads inside a section with “Subtract this area”.
- Give a section its own depth only when your plan calls for it, for example a deeper parking pad.
One layer or two
Some plans use two materials: a coarser layer underneath and a finer layer on top. If yours does, turn on the second layer and enter its depth and density. Each layer is ordered and counted on its own line, and delivery loads are counted separately for each layer, because a truck normally carries one material at a time.
Worked example
A driveway with a main run, a parking pad and a small corner flare, all 4 in deep, using the default allowances and a 10-ton truck. Load it with the “Try the worked example” button.
| Section | Shape and size | Area |
|---|---|---|
| Main driveway | Rectangle, 40 × 12 ft | 480 ft² |
| Parking pad | Rectangle, 15 × 10 ft | 150 ft² |
| Corner flare | Triangle, base 8 ft, height 6 ft | 24 ft² |
| Net area | 654 ft² |
At 4 in (one third of a foot), the compacted volume is 654 ÷ 3 = 218 ft³, or 8.07 yd³. Adding 15% for compaction and 5% for waste multiplies that by 1.20, so the order is 9.69 yd³. At 2,800 lb per cubic yard that weighs about 27,129 lb, or 13.56 US tons, which needs 2 loads on a 10-ton truck. In 0.5 ft³ bags, the same job would be 524 bags, which shows why bags rarely make sense at driveway scale.
Yards, tons and how suppliers sell gravel
Some suppliers price gravel by volume and others by weight. The planner converts between the two with the density you enter. Density changes with the type of stone, its size and how wet it is, so the default is only a starting point; ask your supplier for the figure they use. Note that a US ton is 2,000 lb (907 kg), while a metric tonne is 1,000 kg. The planner shows US tons in Imperial mode and tonnes in Metric mode.
Important assumptions
- Depth is the finished, compacted depth from your plan.
- Compaction (15%) and waste (5%) are added together, so the order is the net volume × 1.20 with the defaults.
- Density starts at 2,800 lb/yd³ (1,660 kg/m³) as a general figure for crushed stone.
- Delivery loads divide the weight of each layer by the truck capacity you enter and round up.
- Bags use the volume printed on the bag, 0.5 ft³ (20 L) by default, and are always rounded up.
What this tool does not calculate
- The depth, base design, drainage, slope or culverts a driveway needs.
- Excavation volume, haul-away, grading or soil stabilization.
- Landscape fabric, edging or border materials.
- Prices, delivery availability or whether a truck can reach your site.
Gravel calculator FAQ
How deep should a gravel driveway be?
This planner does not recommend a depth. The right depth depends on the traffic, the soil, drainage and the material, so enter the depth from your project plan or your supplier’s guidance. If one part needs more depth than the rest, such as a parking pad, give that section its own depth.
Why is compaction added to the order?
Loose gravel takes up more space than the same gravel after it has been compacted. The compaction allowance adds extra material so the finished, compacted layer can still reach the depth you planned. The default is 15%; your supplier may suggest a different figure for their material.
Should I buy gravel in bags or by the ton?
Bags can work for a short garden path, but a driveway quickly needs hundreds of them. That is why the planner lists bulk first and shows bags only as a reference. It still gives both numbers, so you can compare prices if you want to.
How do I handle a curved driveway?
Split the curve into several shorter sections that are close to rectangles or trapezoids, and add each one. If you already know the area from a site plan, choose Known area for that part instead. Small errors at the edges are covered by the waste allowance.
Related planners
Gravel quantities are estimates. Density, compaction and how a supplier measures a load vary, so confirm the order with your supplier. See how we calculate for the full method.