Calculate how much 1/4 minus gravel you need in cubic yards and tons for any area using your length, width, and depth.
1/4 Minus Gravel Formula
The calculator works in two steps. First it finds the area you are covering, then it turns that area and your depth into a volume and a weight of 1/4 minus gravel.
The area depends on the shape you select:
Rectangle Area = L * W
Circle Area = pi * (D / 2)^2
Triangle Area = 0.5 * b * h
The volume in cubic yards and the weight in tons come from the area, the depth, and the material density:
CY = (Area * Depth_ft) / 27
Tons = CY * Density
- L, W: length and width of a rectangular area, in feet.
- D: diameter of a circular area, in feet.
- b, h: base and height of a triangular area, in feet.
- Area: the surface area you are covering, in square feet.
- Depth_ft: the gravel depth in feet. If you enter depth in inches, divide by 12 to get feet.
- CY: the volume in cubic yards. There are 27 cubic feet in one cubic yard.
- Density: the weight of the gravel per cubic yard, in tons. 1/4 minus is about 1.4 tons per cubic yard.
- Tons: the weight of gravel you need to order.
Enter your shape and size to get the area, set the depth to get the cubic yards, and the calculator multiplies by density to return tons. Most suppliers sell 1/4 minus by the ton, so the tons figure is the one you order from. Turning on the cost option multiplies the tons by your price per ton for a quick total.
1/4 Minus Weight and Coverage Reference
1/4 minus is a crushed gravel where every piece is 1/4 inch or smaller, mixed with stone dust. The fines let it pack down tight, so its weight per cubic yard sits near the high end for loose gravel. Use the density values below to convert volume to tons, and the coverage values to sanity check how far one ton goes.
| Material | Tons per cubic yard | Approx. pounds per cubic yard |
|---|---|---|
| 1/4 minus (compacted) | 1.4 to 1.5 | 2,800 to 3,000 |
| 1/4 minus (loose) | 1.3 to 1.4 | 2,600 to 2,800 |
| General crushed gravel | 1.4 to 1.7 | 2,800 to 3,400 |
At a density of 1.4 tons per cubic yard, one ton of 1/4 minus is about 0.71 cubic yards, or 19.3 cubic feet. The table below shows how much area that one ton covers at common depths.
| Depth | Coverage per ton |
|---|---|
| 1 inch | about 231 sq ft |
| 2 inches | about 116 sq ft |
| 3 inches | about 77 sq ft |
| 4 inches | about 58 sq ft |
| 6 inches | about 39 sq ft |
Example Problems
Example 1: Rectangular driveway. You are topping a driveway that is 20 feet long and 10 feet wide with 3 inches of 1/4 minus. The area is 20 * 10 = 200 square feet. Three inches is 0.25 feet, so the volume is 200 * 0.25 = 50 cubic feet, which is 50 / 27 = 1.85 cubic yards. At 1.4 tons per cubic yard that is 1.85 * 1.4 = 2.59 tons.
Example 2: Circular pad. You are filling a round pad 12 feet across with 2 inches of gravel. The area is pi * (12 / 2)^2 = 113.1 square feet. Two inches is 0.167 feet, so the volume is 113.1 * 0.167 = 18.85 cubic feet, which is 0.70 cubic yards. That works out to 0.70 * 1.4 = 0.98 tons, so you would round up to one ton.
Frequently Asked Questions
What does 1/4 minus mean? It is crushed rock screened so the largest pieces are 1/4 inch, blended with all the smaller chips and stone dust down to fine powder. The mix of sizes is what lets it compact into a hard, stable surface, which is why it is common for pathways, shed bases, and driveway topcoats.
How deep should I lay 1/4 minus? For walkways and light foot traffic, 2 inches is usually enough. For driveways and areas that carry vehicles, plan on 3 to 4 inches over a prepared base. Deeper layers should be placed and compacted in lifts of about 2 to 3 inches so the whole depth packs evenly.
Should I order extra? Yes. Add about 5 to 10 percent to the calculated tons to cover compaction, uneven ground, and minor spillage. The calculator gives the theoretical amount, so rounding up keeps you from running short near the end of the job.
