Free Decomposed Granite Calculator
Use this decomposed granite calculator to see how much DG to order for the finished depth you want.
Decomposed granite (DG) is granite weathered into small particles and fines. Spread and compacted, it makes a firm, natural-looking surface for paths and patios.
Because it is compacted in layers, you need more loose DG than the finished depth. The calculator adds 15% by default.
Decomposed granite example: a garden path
A 30 ft long, 4 ft wide path at 3 in deep: 120 sq ft × 3 in ÷ 12 = 30 cu ft, plus 15% extra = 34.5 cu ft. Divide by 27 to get 1.28 cubic yards, which weighs about 1.79 tons, or 69 × 0.5 cu ft bags.
How deep should decomposed granite be?
| Use | Depth | Notes |
|---|---|---|
| Garden path | 2 to 3 in | Compacted in two layers. |
| Patio | 3 in | Over a few inches of compacted base in soft soils. |
| Light driveway | 4 in or more | Over a crushed stone base. |
Coverage per cubic yard and per bag
| Depth | Sq ft per cubic yard | Sq ft per 0.5 cu ft bag |
|---|---|---|
| 1 in | 324 | 6 |
| 2 in | 162 | 3 |
| 3 in | 108 | 2 |
| 4 in | 81 | 1.5 |
Buying tips
- Wet the DG lightly and compact each 1 to 2 inch layer with a plate compactor or hand tamper.
- Stabilised DG (with a binder) resists erosion and tracking better on slopes and in rainy areas.
- Steel or timber edging keeps the edges from crumbling.
How much does decomposed granite weigh?
A cubic yard of decomposed granite typically weighs 2,600 to 3,000 lb (1.3 to 1.5 tons). The calculator uses 2,800 lb (1.4 tons) per cubic yard. Moisture and grading change the weight, so if your supplier sells by the ton, ask for their figure.
Frequently asked questions
How much does a yard of decomposed granite weigh?
About 2,600 to 3,000 lb, or roughly 1.4 tons per cubic yard.
How deep should decomposed granite be?
About 2 to 3 inches compacted for paths and patios, more for areas that carry vehicles.
How much area does a yard of DG cover?
About 108 sq ft at 3 inches deep before compaction, or about 94 sq ft once you allow 15% for compaction.
How accurate is this decomposed granite calculator?
The decomposed granite calculator gives the exact volume for the measurements you enter, then adds 15% extra (you can change it). Weights use a typical 1.4 tons per cubic yard; real loads vary with moisture, so confirm with your supplier if you buy by the ton. Measure carefully: an error of one inch in depth changes a 3 inch layer by a third.
How the decomposed granite calculator works
Volume = area × depth. Each area is worked out from its shape (length × width, π × radius², or ½ × base × height), converted to square feet, multiplied by the depth in feet, and added up. Cubic feet ÷ 27 = cubic yards.The extra percentage is then added, and bag counts are rounded up to whole bags. See how we calculate for every figure we use.