Decomposed Granite Calculator
Decomposed granite is one of the few landscape materials that is both the surface you walk on and a material that compacts — a garden path, patio, or xeriscape ground you tamp firm and then step on directly, with no paving over it. It is crushed granite weathered down to fines, in tan, gold, gray, or mixed earth tones depending on the quarry. Two decisions shape a DG job: how much to order once it settles under tamping, and whether to leave it natural or bind it with a stabilizer so it resists rain and traffic. This page sizes the first; the prose below walks the second.
Total weight ≈ 2,534.98 lb (1.27 tons). Bulk material is heavy — check your vehicle's payload/GVWR; over ~1 ton, delivery is usually safer than hauling it yourself.
Bag or bulk?
You need about 0.91 cubic yards (1.27 tons). This material has no standard bagged option — order it loose (bulk) and have it delivered in one drop. Plan for a loose delivery or pickup rather than bags.
Quantities are planning estimates — confirm with your supplier.
How it works
A walkable DG path or patio is usually 2–3 inches of compacted material over a firm subgrade. From the shape and depth you set above, the calculator takes the in-place volume (area × depth) — the finished surface you actually want underfoot — and works in feet, inches, yards, or metric.
Because the surface you walk on is the DG itself, it has to finish exactly at the grade you screed it to — flush with the edging, gently crowned so rain runs off. The catch is that DG is crushed fine, so when you tamp or plate-compact it the fines knit together and the layer settles roughly 25%: rake it level at your target depth, pack it, and it drops below the edge, leaving a path that sits low and feels loose underfoot. So the calculator sizes the looser delivered volume that lands at full depth once it is packed — a bit more than the finished surface needs: order = in-place ÷ (1 − settlement) × (1 + waste). At the 25% settlement default that is about 1.33× the in-place volume before the default 10% waste, which covers spillage, screeding off the high spots, and feathering into the edges. Skip that step — order only the finished depth — and the path comes up thin.
The result is cubic yards and tons at DG's loose density near 2,800 lb/yd³, plus the total weight to match against your truck's payload and GVWR before you haul a load. This page sizes DG as a bulk order, the way path- and patio-scale jobs are usually bought; bagged DG does exist (often 50 lb / 0.5 cu ft sacks), but bag volumes vary by supplier, so for a small job check the cubic-foot volume printed on the bag and divide your ordered cubic feet by it. For ordering, treat the DG volume as the same whether you leave it natural or stabilize it — a stabilizer is a binder, often a liquid polymer or a plant-based powder depending on the product, mixed into or applied through the same well-graded fines rather than a different stone — so that choice is about how the finished surface wears, covered next, not about how much to order.
Worked example
Garden path, 40 ft × 3 ft, 3 in compacted DG, 25% settle
Building a 40 ft × 3 ft garden path 3 inches deep with decomposed granite, tamped to a firm, walkable surface. DG is crushed fine enough to pack down — it settles about 25% as the fines lock together, so the loose volume you order has to exceed the finished 3-inch path.
Watch the jump from in-place volume to ordered volume: that gap is what you tamp down into the firm, even surface you walk on. Order only the finished depth and the path ends up thin and loose underfoot, sitting low against its edging.
- Area
- 120 sq ft
- Volume (in place)
- 1.11 cu yd
- Order (compaction + waste)
- 1.63 cu yd
- Weight
- 2.28 tons
Coverage at a glance
| Depth | 1 ton covers | 1 cu yd covers |
|---|---|---|
| 2" | 116 sq ft | 162 sq ft |
| 3" | 77 sq ft | 108 sq ft |
| 4" | 58 sq ft | 81 sq ft |
FAQ
How much decomposed granite do I need for a path or patio?
Enter your shape, dimensions, and depth above and the calculator returns cubic yards and tons. A walkable DG path or patio is typically 2–3 inches of compacted material over a firm subgrade. The worked example on this page runs a 40 ft × 3 ft garden path at 3 inches so you can see how the in-place depth turns into the larger volume you actually order once compaction is built in.
Why do I have to order extra DG for compaction?
Because decomposed granite is meant to be tamped, and tamping shrinks it. The fines knit into the gaps and the layer settles about 25% as it packs, so the loose pile you have delivered finishes thinner than the depth you raked it to. To land at your target depth you order the in-place volume divided by (1 − settlement): at 25% that is in-place ÷ 0.75, roughly a third more material. Order only the in-place volume and the path settles below its edging — thin and loose underfoot — instead of sitting flush and firm where you walk.
What is the difference between decomposed granite and crusher run?
What you do with each. Decomposed granite is fine, natural stone in tan, gold, gray, or mixed earth tones that compacts into the walkable finished surface itself — a garden path, patio, or xeriscape area you step on directly. Crusher run is coarse, grey, dust-bound stone that compacts into a structural base hidden under a driveway, carrying vehicle load while something else goes on top. Both pack down about a quarter, but DG is the surface and crusher run is the foundation. If your job is a vehicle-bearing base rather than a path you walk on, size it on the crusher run calculator instead.
Should I use stabilized decomposed granite?
It depends on traffic and slope. Stabilized DG has a binder — often a liquid polymer or a plant-based powder, depending on the product — mixed into or applied through the same fines so the surface sets up firmer and resists scuffing, ruts, and rain-wash, worth the extra cost for high-traffic paths, patios you furnish, or anything on a slope. Natural DG with no binder is cheaper and holds up fine on flat, low-traffic paths and informal xeriscape areas. It is the same fines either way, so for ordering you can treat the volume as unchanged and just pick the finish — natural or stabilized — by how hard the surface has to wear.
Does decomposed granite hold up, or get muddy?
Compacted DG packs hard and can take some infiltration, but it is not a drainage layer — surface water has to shed off it, not soak through it. Crown or slope the path so water runs off, and contain it inside a solid edge so the fines cannot migrate. Where drainage is poor or runoff concentrates, saturated DG can soften, rut, or wash, so on a grade or a busy route blend in a stabilizing binder to lock the fines together and hold the surface.