Estimate 1/4 minus gravel volume in cubic yards and weight in US short tons for rectangular, circular, or triangular areas using the dimensions, depth, and material density.
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 estimated weight in US short 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 gravel per cubic yard, in US short tons. The default 1.4 is an estimating assumption; use your supplier’s value for the material and condition ordered. One US short ton equals 2,000 pounds.
- Tons: the estimated weight in US short tons, before any ordering allowance.
Select the shape and enter its dimensions and depth to calculate cubic yards. The visible density input converts that volume to estimated US short tons. Expand the optional cost section and enter a price per US short ton to estimate material cost; leave the price blank to omit cost. Confirm the density, selling unit, and ordering allowance with your supplier.
1/4 Minus Weight and Coverage Reference
1/4 minus is crushed gravel screened to a nominal 1/4-inch maximum size and mixed with fines. Bulk density varies with the product, moisture, and compaction. The density ranges below are illustrative estimating assumptions, not a supplier specification; their tons are US short tons of 2,000 pounds. Use your supplier’s density for ordering.
| 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 the assumed density of 1.4 US short tons per cubic yard, one US short ton is about 0.71 cubic yards, or 19.3 cubic feet. The table below shows its theoretical coverage at an even depth, before any allowance.
| 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. For an area 20 feet long and 10 feet wide at a depth of 3 inches, the area is 20 * 10 = 200 square feet. Three inches is 0.25 feet, so the volume is 200 * 0.25 = 50 cubic feet. That is 50 / 27 ≈ 1.85 cubic yards. At the assumed density of 1.4 US short tons per cubic yard, the unrounded calculation is (50 / 27) * 1.4 ≈ 2.59 US short tons, before any allowance.
Example 2: Circular pad. For a round area 12 feet in diameter at a depth of 2 inches, the area is pi * (12 / 2)^2 = 36 * pi ≈ 113.10 square feet. Two inches is exactly 1/6 foot, so the volume is 6 * pi ≈ 18.85 cubic feet, or about 0.70 cubic yards. Using unrounded values and the assumed density of 1.4 gives (6 * pi / 27) * 1.4 ≈ 0.98 US short tons. Confirm the ordering amount with your supplier.
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? The appropriate depth and compacted lift thickness depend on the product, prepared base, drainage, expected load, and project specification. Follow your supplier’s installation guidance and your project requirements. This calculator estimates quantity from the depth you enter; it does not determine a suitable construction depth.
Should I order extra? An allowance may be needed for uneven ground, losses, and differences between loose and compacted volume. Confirm the appropriate allowance and density with your supplier for the material and project. The calculator does not add an automatic waste or compaction allowance.
