Decomposed Granite Calculator
A decomposed granite calculator finds tons as L × W × depth ÷ 27 × 1.35. A 15 × 10 ft path at 3 in needs 1.88 tons of DG, or 2.06 tons with 10% added.
What your order looks like
A pickup or a small delivery will do it.
1.39 yd³ · 1.9 tons
19 wheelbarrow trips (2 cu ft each)
3 pickup loads (0.75 ton each)
1 small dump truck load (6 tons each)
Rules of thumb: A wheelbarrow trip is 2 cubic feet of heavy material, about 200 lb, a load most people can push. A pickup load is 0.75 ton, the payload of a full-size half-ton pickup (1,500 lb). A small single-axle dump truck carries about 6 tons.
How much decomposed granite do I need?
This decomposed granite calculator multiplies length × width × depth to get the volume, converts it to cubic yards, then multiplies by 1.35 tons per cubic yard to give the weight to order. The formula is tons = length × width × (depth in inches ÷ 12) ÷ 27 × 1.35. A 15 × 10 ft path at 3 inches deep needs 1.88 tons.
Enter the area in feet, the compacted depth in inches, and the price per ton. Tick the 10% box, because DG loses height when you water and compact it.
The formula in plain words
- Depth to feet: 3 inches ÷ 12 = 0.25 ft
- Volume: length × width × depth in feet = cubic feet
- Cubic yards: cubic feet ÷ 27
- Tons: cubic yards × 1.35
- With waste: tons × 1.10
DG is usually sold by the ton from rock yards and by the cubic yard from some landscape suppliers. This calculator gives tons. To compare with a per-yard quote, divide the tons by 1.35.
Worked examples
- Garden path: 15 ft × 10 ft area, 3 in deep, $50/ton
- Cubic feet: 15 × 10 × 0.25 = 37.5 ft³
- Cubic yards: 37.5 ÷ 27 = 1.389 yd³
- Tons: 1.389 × 1.35 = 1.88 tons, costing $93.75
- With 10% extra: 2.06 tons, costing $103.13
- Patio: 20 ft × 16 ft, 4 in deep, $50/ton
- Cubic feet: 20 × 16 × 0.333 = 106.7 ft³
- Cubic yards: 106.7 ÷ 27 = 3.95 yd³
- Tons: 3.95 × 1.35 = 5.33 tons, costing $266.67
- With 10% extra: 5.87 tons, costing $293.33
A 4-inch patio should go down in two lifts of about 2 inches. Water and compact each lift before adding the next.
Decomposed granite coverage
| Compacted depth | Sq ft per ton | Tons per 100 sq ft | Typical use |
|---|---|---|---|
| 2 in | 120 | 0.83 | Light garden path, mulch replacement |
| 3 in | 80 | 1.25 | Standard walkway |
| 4 in | 60 | 1.67 | Patio, seating area, busier path |
Three kinds of DG
| Type | What it is | Best for |
|---|---|---|
| Natural (loose) DG | Plain weathered granite, no binder | Mulch-like ground cover, low-traffic areas |
| Stabilized DG | DG blended with a binder before compaction | Patios, sloped paths, accessible routes |
| Resin-coated DG | DG bound with a resin product | High-use paths where a near-paved finish is wanted |
All three weigh about the same per cubic yard, so this calculator works for each. Stabilizer is priced separately when it is not premixed.
Bags or bulk?
Some garden centers sell DG in bags of about half a cubic foot. One ton at 1.35 tons per yard is 20 cubic feet, so it equals roughly 40 of those bags. For the 1.88-ton path in example 1, that is about 75 bags. Bulk delivery is usually far cheaper above half a ton, although a delivery fee may apply.
How to lay and measure DG
- Excavate for the full depth. Dig out the path depth plus any base layer, so the finished DG sits flush with or just below the edging.
- Use the compacted depth. Loose DG spread 3.5 inches thick compacts to about 3 inches. The 10% box covers this. Raise it toward 15% for thick patios.
- Lay fabric on weedy ground. A woven landscape fabric under the base slows weeds and keeps the base from mixing into soil.
- Measure curving paths in segments. Take the width every few feet, average it, and multiply by the centerline length.
Common DG mistakes
- No base on clay. Clay heaves when wet. Without a few inches of compacted crushed rock beneath, the DG cracks and puddles.
- One thick lift. Compacting 4 inches at once leaves the bottom loose. Work in lifts of 2 inches or less.
- No slope for drainage. Give the surface a slight cross-slope so water runs off instead of washing the fines out.
- Mixing up DG and crushed granite. Crushed granite is a screened angular stone. It drains well but does not bind like DG. See the crushed granite calculator.
For loose path materials, compare the pea gravel calculator and the gravel path calculator.
Frequently asked questions
What is decomposed granite?
Decomposed granite (DG) is granite rock weathered down into small fragments mixed with sand- and silt-sized fines. Those fines fill the gaps between the larger grains when the DG is watered and compacted. The result is a firm, natural-looking surface rather than loose gravel.
How many tons of decomposed granite do I need per 100 sq ft?
At 1.35 tons per cubic yard, 100 sq ft takes about 0.83 tons at 2 inches, 1.25 tons at 3 inches, and 1.67 tons at 4 inches. Add about 10% for compaction and edges.
Do I need to add a stabilizer to decomposed granite?
Plain DG works for light-traffic garden paths. For patios, sloped paths, wheelchair routes, and seating areas, stabilized DG is mixed with a binder before compaction. It erodes less, sheds less dust, and stays put better. Some yards sell it premixed, so check before ordering.
How deep should a decomposed granite path be?
Plan on about 2 to 3 inches of compacted DG for a garden path over firm soil, and 3 to 4 inches for patios or busier walkways, placed in lifts of 1.5 to 2 inches. On soft or clay soils, put a compacted base of crushed rock under it first.
Does decomposed granite need edging?
Yes, in almost every case. DG compacts but is not rigid, so without a border it creeps into lawns and beds and the path edges crumble. Steel, aluminum, stone, or paver edging set slightly above the finished surface holds it in place.
How often does a decomposed granite surface need to be refreshed?
It depends on traffic, slope, and rainfall. Busy, unstabilized paths often need a thin top-dress every couple of years as fines wash out. Rake in new material, wet it, and roll or tamp it so it bonds to the layer below.
Estimates only. Verify quantities with your supplier before purchasing.