Key numbers
- Formula: yd³ = ft² × depth (in) ÷ 324; tons = yd³ × density (t/yd³)
- Density: no published standard for DG; the calculator uses 1.4 t/yd³ (1.66 t/m³) as a planning value. Type your supplier's figure to override it
- Coverage: 1 yd³ covers 108 ft² at 3 in, 81 ft² at 4 in
- Accessible paths must be firm and stable (FHWA trail guidance); plain DG usually needs a stabilizer and compaction to get there
On this page
- How to use the Decomposed Granite Calculator
- How do you calculate decomposed granite?
- How much does decomposed granite weigh per cubic yard?
- Decomposed granite coverage by depth (chart)
- How much DG do I need for common path and patio sizes?
- Natural, stabilized and resin-bound DG: does the amount change?
- Decomposed granite in metric
- Common decomposed granite mistakes
- Frequently asked questions
How to use the Decomposed Granite Calculator
- 1Describe the areaChoose Rectangle (length × width), Circle (diameter) or Known area if you already have the square footage.
- 2Pick your unitsUse US (feet and inches) or Metric (meters and centimeters). Switching converts the numbers you typed, so the area stays the same.
- 3Enter the depthType how deep the decomposed granite (planning value, use supplier figure) should be, 3 in is a common starting point for this job.
- 4Choose the materialThe calculator uses 1.4 tons per cubic yard for decomposed granite (planning value, use supplier figure). Use your supplier's figure if it differs.
- 5Allow for settlingChoose the extra: none, 5%, 10% (the default) or 20% for a base you will compact.
- 6Read and price the resultsSee cubic yards, cubic feet, cubic meters, US tons and metric tonnes and the number of 0.5 ft³ bags. Enter your supplier's price per ton for the total cost.
Results update as you type. Back to the calculator ↑
How do you calculate decomposed granite?
Multiply the area by the depth to get volume, add an allowance for compaction, then convert to tons with your supplier’s density. The calculator above does all three and also gives metric and bag counts.
Cubic yards = length (ft) × width (ft) × depth (in) ÷ 324
Tons = cubic yards × density (tons per yd³)
The 324 is 27 ft³ per cubic yard × 12 in per foot, so it turns square feet times inches straight into cubic yards. In metric, cubic metres = length (m) × width (m) × depth (m).
- Measure the area. Split curved beds into rectangles, or use the Circle or Known area option.
- Pick the finished depth from your plans or the stabilizer instructions.
- Choose an allowance. DG arrives loose and is compacted, so 10% is the default; choose more for heavy compaction.
- Enter your supplier’s density if they quote one. Otherwise the 1.4 t/yd³ planning value applies.
Worked example: 4 × 30 ft garden path, 3 in deep
- Area: 4 × 30 = 120 ft² (11.15 m²)
- Volume: 120 × 3 ÷ 324 = 1.11 yd³ (30 ft³, 0.85 m³)
- With 10% extra for compaction: 1.22 yd³
- Weight at 1.4 t/yd³: 1.22 × 1.4 = 1.71 tons
- In 0.5 ft³ bags: 33 ft³ ÷ 0.5 = 66 bags
If the yard quotes 1.5 t/yd³ instead, type 1.5 into the density box: the same 1.22 yd³ becomes about 1.83 tons.
How much does decomposed granite weigh per cubic yard?
There is no single figure. DG is weathered granite broken down to fine gravel and grit, and its weight depends on the quarry, the grading, how much fines it holds and how wet it is. We found no government, university or standards-body table for it, so this page does not state one as fact.
The calculator starts at 1.4 tons per cubic yard (about 1.66 t/m³), a planning value in the same range the site uses for other loose aggregates. It is there so the tool gives a weight at all; it is not a measured density. Ask the yard for its tons per yard, or weigh a truck in and out, and type that into the “Your supplier’s density” box.
Why it matters. Many yards sell DG by the ton but you design by depth. A 10% error in density is a 10% error in the tons you pay for. On a 4 yd³ order, the difference between 1.3 and 1.5 t/yd³ is 0.8 tons.
Decomposed granite coverage by depth (chart)
One cubic yard covers 324 ÷ depth (in) square feet. The tons columns use the 1.4 t/yd³ planning value; scale them for your supplier’s figure.
| Depth | ft² per yd³ | ft² per ton (1.4 t/yd³) | m² per m³ |
|---|---|---|---|
| 2 in (50 mm) | 162 | 116 | 20 |
| 3 in (75 mm) | 108 | 77 | 13.3 |
| 4 in (100 mm) | 81 | 58 | 10 |
How much DG do I need for common path and patio sizes?
Volumes before and after a 10% compaction allowance, with tons at 1.4 t/yd³ and bag counts for 0.5 ft³ bags (including the 10%).
| Area | Depth | yd³ | yd³ +10% | Tons +10% | 0.5 ft³ bags +10% |
|---|---|---|---|---|---|
| 3 × 20 ft path | 3 in | 0.56 | 0.61 | 0.86 | 33 |
| 4 × 30 ft path | 3 in | 1.11 | 1.22 | 1.71 | 66 |
| 10 × 10 ft patio | 3 in | 0.93 | 1.02 | 1.43 | 55 |
| 12 × 12 ft patio | 3 in | 1.33 | 1.47 | 2.05 | 80 |
| 20 × 20 ft area | 3 in | 3.70 | 4.07 | 5.70 | 220 |
| 10 × 20 ft parking pad | 4 in | 2.47 | 2.72 | 3.80 | 147 |
| 12 × 24 ft parking pad | 4 in | 3.56 | 3.91 | 5.48 | 212 |
| 12 × 50 ft driveway | 4 in | 7.41 | 8.15 | 11.41 | 440 |
Bags make sense for a small path; past about one cubic yard the bag count climbs into the hundreds and bulk delivery is usually simpler. Areas that carry cars normally sit on a compacted aggregate base, which is a separate layer: size it with the crusher run calculator or gravel calculator.
Natural, stabilized and resin-bound DG: does the amount change?
The volume formula is the same for all three. What changes is how much you compact, what you add, and what the supplier recommends.
- Natural (loose) DG is the plain material. It packs down under foot traffic but can wash out on slopes and track indoors.
- Stabilized DG is DG blended with a binder, at the yard or on site, then wetted and compacted. It holds up better on paths and gentle slopes. The binder maker sets the depth, mixing rate and compaction, so follow their sheet.
- Resin-bound or resin-coated DG uses a resin binder and gives the firmest surface. It is usually installed by the product’s own contractors.
Accessible paths. FHWA’s trail design guidance says a trail surface must be “firm and stable for accessibility”, and lists keeping roots, rocks, ruts and bumps under 2 inches. Loose DG on its own often does not stay firm under a wheelchair, so accessible routes usually use a stabilized product, a compacted base and edging. If the path must meet an accessibility standard, check the requirement with the designer or the authority that enforces it.
Decomposed granite in metric
Use cubic metres directly: area (m²) × depth (m). At the planning value of 1.4 short tons per cubic yard, DG is about 1.66 tonnes per m³.
Worked example: 1.2 × 10 m path, 75 mm deep
- Area: 1.2 × 10 = 12 m²
- Volume: 12 × 0.075 = 0.9 m³
- Weight at 1.66 t/m³: about 1.5 tonnes, or 1.64 tonnes with 10% extra
Switch the calculator to Metric and enter your supplier’s density in t/m³ to override the planning value.
Common decomposed granite mistakes
- Taking any weight as fact. DG density varies by source; one number from the internet can be off by a few tenths of a ton per yard.
- Ordering the finished volume. Compaction shrinks it. Add 10% or more.
- Skipping edging. Without a hard edge, DG spreads into beds and lawn and the path gets thinner.
- Laying vehicle areas on soil. Put a compacted aggregate base under DG that carries cars.
- Mixing stabilizer by eye. Follow the binder maker’s rate, water and compaction instructions.
- Forgetting drainage. Water standing on DG softens it. Give the surface a slight fall away from buildings.
Results are ordering estimates. Your supplier’s density and your plans or product instructions take priority.
FAQ
Frequently asked questions
How much decomposed granite do I need for a 10×10 area?
At 3 in deep, 100 ft² needs 0.93 yd³ (25 ft³), or 1.02 yd³ with 10% extra. At a 1.4 t/yd³ planning value that is about 1.43 tons; at 4 in deep it is 1.23 yd³ before the extra.
How much does a ton of decomposed granite cover?
At 1.4 tons per cubic yard, a ton covers about 116 ft² at 2 in, 77 ft² at 3 in and 58 ft² at 4 in. A denser or wetter DG covers less per ton, so use your supplier's weight.
How much does a cubic yard of decomposed granite weigh?
It varies by quarry, grading and moisture, and we found no government or standards figure. This calculator uses 1.4 tons per yd³ (about 1.66 t/m³) as a planning value. Ask the yard for its weight and enter it.
How deep should decomposed granite be?
It depends on use, soil and the product, and there is no single standard. Paths for walking are usually thinner than areas that carry vehicles. Follow your plans or the stabilizer maker's instructions; the table shows 2, 3 and 4 in for comparison.
How many bags of decomposed granite do I need?
Divide the cubic feet by the bag size. A 3 × 20 ft path at 3 in is 15 ft³; with 10% extra that is 33 bags of 0.5 ft³. For more than about one cubic yard, bulk delivery is usually simpler.
Should I add extra for compaction?
Yes. DG is delivered loose and compacted in place, so order more than the finished volume. The calculator defaults to 10%; pick 15–20% if you will compact hard. Ask the supplier how much their material settles.
How much decomposed granite per square metre?
Multiply area by depth in metres. At 75 mm deep each m² takes 0.075 m³. A 1.2 × 10 m path is 0.9 m³, about 1.5 tonnes at the 1.66 t/m³ planning value, or 1.64 tonnes with 10% extra.
2 Sources
Last reviewed October 10, 2026 by M Bilal. Found an error? Tell us.