How Much Is Decomposed Granite? Cost Guide

Decomposed granite (DG) costs $1 to $3 per square foot for the material alone, with a typical installed price of $3 to $7 per square foot depending on depth, location, and whether you DIY. For a 500-square-foot project at 3 inches deep, expect to pay roughly $150–$450 for the DG itself, or $1,500–$3,500 if professionally installed with prep and compaction.

Formula

The calculator figures out how much decomposed granite you need by volume. The formula is:

Volume (yd³) = (Length × Width × Depth) / 324

Where:

• Length = the length of the area in feet (ft)
• Width = the width of the area in feet (ft)
• Depth = the depth of the DG layer in inches (in)
• 324 = the conversion factor (1 cubic yard = 27 cubic feet; 27 × 12 inches per foot = 324)

For cubic feet, use: Volume (ft³) = (Length × Width × Depth) / 12

Worked Example

Using the default values from the calculator: a 40 ft long, 25 ft wide area with a 3-inch depth.

1. Convert depth to feet: 3 in ÷ 12 = 0.25 ft
2. Calculate volume in cubic feet: 40 × 25 × 0.25 = 250 ft³
3. Convert to cubic yards: 250 ÷ 27 = 9.26 yd³ (rounded to 9.26)

The calculator’s first output shows 9.26 yd³, matching the manual calculation. The second output shows 250 ft³.

What Affects the Price of Decomposed Granite

Several factors move the final cost up or down. Knowing them helps you budget accurately and avoid surprises.

• Depth: Most residential paths use 2–3 inches. Driveways need 4–6 inches for vehicle weight. Doubling the depth doubles the material cost.
• Quality and color: Standard tan or brown DG is cheapest. Specialty colors (gold, grey, red, or blue) cost more because they are quarried in fewer locations. Stabilized DG (mixed with a resin or glue) can be 2–3 times the price of loose DG.
• Delivery fees: Bulk delivery is usually free within a certain radius but can add $50–$150 for longer distances. Bagged DG (sold in 0.5 or 1 cubic foot bags) costs more per cubic foot but is easier for small patches.
• Labor: Professional installation includes site prep (removing grass, grading), laying landscape fabric, spreading the DG, and compacting. DIY saves labor but requires renting a plate compactor (about $50–$80 per day) and a lot of physical work.
• Location: Prices vary by region due to quarry proximity and local demand. Urban areas tend to have higher delivery and labor rates.

How to Choose the Right Type of DG

Not all decomposed granite is the same. The right choice depends on where you’re using it and how much traffic it gets.

• Loose DG: Best for low-traffic garden paths, mulch replacement, or decorative borders. It stays soft and natural but needs occasional raking to stay even.
• Stabilized DG: Mixed with a binder (often a plant-based polymer or resin). It hardens into a more solid surface, resists erosion, and is suitable for driveways, patios, and slopes. It’s more expensive but lasts longer with less maintenance.
• Decomposed granite fines: These are the smallest particles, sometimes called “minus 1/4 inch.â€� They compact tightly and are ideal for paths and patios. Coarser DG with larger stones (up to 1/2 inch) drains better and is better for driveways.

Check with your local supplier for what’s available in your area. Some quarries sell “decomposed granite� that is actually crushed rock, which has a different look and compaction behavior.

Common Problems and How to Avoid Them

DG is a popular choice, but it has a few downsides that surprise homeowners.

• Washout on slopes: Loose DG erodes in heavy rain. Use stabilized DG or install edging (such as steel or concrete curbs) to keep it in place.
• Weeds: DG doesn’t prevent weeds. Lay a weed barrier fabric underneath to reduce maintenance. Without it, weeds will pop through within a season.
• Dust: In dry climates, DG can get dusty. A light spray of water settles it, but dust returns. Stabilized DG minimizes this.
• Ruts and displacement: Vehicle tires and foot traffic can create ruts. Compact the base thoroughly and consider a thicker layer for driveways.
• Tracking into the house: Small particles stick to shoes. A transition area (like a stepping stone or mat) helps reduce tracking.

Cost Comparison: DG vs. Alternatives

To know if DG is a good deal, compare it with other common hardscape materials. Prices are approximate and vary by region.

• Gravel (crushed stone): $1–$2 per square foot (material only). Similar to DG but with larger, more angular pieces. Gravel drains better but is less comfortable to walk on barefoot.
• Mulch (wood chips): $0.50–$1.50 per square foot. Cheaper but decomposes and needs replacement every 1–2 years.
• Concrete (poured): $6–$12 per square foot installed. Durable and low-maintenance but much more expensive and not permeable.
• Pavers (concrete or brick): $10–$20 per square foot installed. High-end look, but the highest cost of these options.

DG offers a middle ground: it looks natural, is permeable (helps with drainage), and costs less than hard surfaces. The tradeoff is that it needs occasional replenishment (a 1-inch top-up every few years).

How to Install Decomposed Granite (DIY Steps)

If you’re handy and want to save on labor, here’s the basic process for a standard path or patio.

1. Mark the area and remove any grass or plants. Use a shovel or sod cutter.
2. Excavate to the depth of your DG layer plus 1–2 inches for a base. For a 3-inch DG layer, dig down about 4–5 inches.
3. Compact the soil with a hand tamper or plate compactor.
4. Lay landscape fabric over the compacted soil to block weeds.
5. Add a base layer of crushed rock (optional but recommended for driveways or high-traffic areas). Compact it.
6. Spread the DG in 2–3 inch lifts (layers). For each lift, spray with water and compact with a plate compactor.
7. Finish with a final compaction and check for evenness.

For a 500-square-foot area, expect the DIY work to take a weekend (with help) and require renting a compactor. The main savings are on labor, which can be 50–70% of the installed cost.

Frequently Asked Questions

How much decomposed granite do I need for a 10×10 patio?

For a 10×10 foot area (100 sq ft) at 3 inches deep, you need about 0.93 cubic yards (25 cubic feet). That’s roughly 1 cubic yard when rounded up for compaction. Use the calculator above with length=10, width=10, depth=3 to get the exact figure.

Can I just pour DG over grass?

No. Grass will decompose and create an uneven surface, and weeds will push through. You must remove the grass and compact the soil first. Skipping this step leads to a bumpy, weedy path within months.

How deep should decomposed granite be?

For foot traffic, 2–3 inches is standard. For driveways or areas with vehicles, use 4–6 inches. Deeper layers compact better and resist ruts, but cost more in material.

Does decomposed granite harden like concrete?

Loose DG does not harden; it stays somewhat loose even after compaction. Stabilized DG, which contains a binder, does harden into a solid surface. If you want a concrete-like finish, choose stabilized DG.

How long does decomposed granite last?

Loose DG can last 5–10 years with minimal maintenance, but you’ll need to add a thin layer every few years to replace what washes or kicks away. Stabilized DG can last 10–15 years or more, especially in dry climates.

Is decomposed granite safe for pets?

Yes, DG is generally safe for pets. It’s non-toxic and doesn’t contain chemicals. However, the fine dust can irritate some animals’ paws or lungs if they dig or run on it heavily. Rinse paws after walks if your pet is sensitive.

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in l | Lawn length | ft | 40 | 0 | 100000
in w | Lawn width | ft | 25 | 0 | 100000
in d | Depth | in | 3 | 0 | 120
out yd | Volume | yd³ | l * w * d / 324 | 2
out ft3 | Volume | ft³ | l * w * d / 12 | 1