Decomposed Granite Calculator
Find out how much decomposed granite to order — accounting for compaction — for a pathway, patio or driveway.
Your area
Sets a compacted depth of 2 in — adjust below if needed.
How much the loose material shrinks once compacted. 15–20% is typical.
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Bags or bulk delivery?
Order bulk by the ton
Loose vs compacted
Material profile
The short answer
Decomposed granite compacts roughly 15–20% once placed and rolled, so you need to order more loose material than your finished depth suggests. Divide the compacted depth by (1 minus the compaction factor) to get the loose depth to order — a 2 inch finished pathway needs about 2.35 inches of loose material spread before compacting.
Decomposed granite needed for common areas
Figures below use a 15% compaction factor and natural DG density, before waste.
| Area size | Compacted depth | Loose cubic yards | Loose tons |
|---|---|---|---|
| 5 × 10 ft path | 2″ | 0.33 yd³ | 0.44 t |
| 10 × 10 ft path | 2″ | 0.65 yd³ | 0.88 t |
| 12 × 12 ft patio | 3″ | 1.41 yd³ | 1.90 t |
| 10 × 20 ft driveway strip | 4″ | 2.61 yd³ | 3.53 t |
| 20 × 20 ft patio | 3″ | 3.92 yd³ | 5.29 t |
Natural vs stabilized decomposed granite
| Natural (unstabilized) | Stabilized (resin-bound) | |
|---|---|---|
| Cost | Lower | Higher, plus binder |
| Compaction | ~15–20% | ~10–15%, sets firmer |
| Best for | Pathways, patios, light use | Driveways, high traffic, erosion-prone areas |
| Maintenance | Top-up or re-compact every 1–3 years | Minimal for 5+ years |
| Permeability | Good drainage | Still permeable, slightly reduced |
How to calculate decomposed granite, accounting for compaction
- Decide the finished, compacted depth. 2″ for a pathway, 3″ for a patio, 4″+ for a driveway.
- Account for compaction. Divide by (1 − compaction factor) to find the loose depth to spread before rolling.
- Find the loose volume. Multiply the loose depth by your area to get cubic feet, then divide by 27 for cubic yards.
- Add waste. 5–10% covers spillage and edge loss.
- Convert to weight. Multiply cubic yards by density (roughly 2,700–2,800 lb/yd³), then divide by 2,000 for tons.
Worked example
A 10 × 10 ft pathway, 2 inches compacted, natural DG, 15% compaction factor:
- Area10 × 10 = 100 sq ft
- Loose depth2 ÷ (1 − 0.15) = 2.35 in
- Loose depth in feet2.35 ÷ 12 = 0.196 ft
- Loose cubic feet100 × 0.196 = 19.6 cu ft
- Loose cubic yards19.6 ÷ 27 = 0.73 yd³
- Plus 10% waste0.80 yd³
- Weight0.80 × 2,700 = 2,160 lb ≈ 1.1 tons
Installation checklist
- Excavate and compact the subgradeRemove organic material and compact the exposed soil before adding DG.
- Install edge restraintMetal, plastic or paver edging keeps loose material from migrating outward.
- Add a base layer for drivewaysA compacted aggregate base underneath improves stability under vehicle loads.
- Spread in lifts2 inch lifts, compacted with a plate compactor between each, for anything over 3 inches total.
- Mix in stabilizer if using itFollow the product’s mixing ratio, then compact while still workable.
- Water and re-compactA light watering before final compaction helps natural DG bind together.
Common mistakes
- Ordering the finished depth instead of the loose depthThis is the single most common shortfall — always divide by the compaction factor before ordering.
- Skipping edge restraintLoose DG spreads outward onto lawns and adjacent surfaces without a physical edge to contain it.
- Under-compactingA surface that isn’t properly rolled stays loose and rutted underfoot, and erodes faster in rain.
- Using natural DG on a driveway without a baseVehicle loads need a compacted aggregate base underneath, not DG directly on subgrade.
- Confusing DG with regular decomposed gravel or crushed stoneDG’s fine particle mix is what allows it to compact into a firm surface — a coarser aggregate won’t behave the same way.
- Skipping the compaction factor because it seems like “extra”It isn’t extra — it’s the difference between what you buy and what actually ends up as your finished surface.
What this calculator assumes
Adjust your result if your project differs from these.
- Uniform compacted depth across the whole area
- Density of about 2,700 lb/yd³ for natural DG and 2,800 lb/yd³ for stabilized
- A compaction factor you set, typically 15–20% for natural and 10–15% for stabilized
- A bag size of 0.5 cubic feet, a common hardware-store size
- Stabilizer coverage of roughly 100 sq ft per gallon, when selected — check your specific product
- Bulk orders rounded up to the nearest quarter ton
- Prices are whatever you enter; they are not live market rates
Common questions
How much does decomposed granite compact?
Roughly 15 to 20 percent of its loose depth once placed and compacted, depending on the material’s fines content and how well it’s rolled or tamped.
How deep should decomposed granite be?
2 inches compacted for a pathway, 3 inches for a patio, and 4 inches or more, sometimes in two layers, for a driveway or vehicle area.
What is the difference between stabilized and natural decomposed granite?
Natural decomposed granite is the loose, unmodified material and needs regular compaction and occasional top-ups. Stabilized decomposed granite has a resin binder mixed in, which sets firmer, resists erosion better, and needs less maintenance, at a higher cost.
How many tons of decomposed granite do I need?
A 10 × 10 ft pathway at a 2 inch compacted depth needs roughly 0.7–1 tons of loose decomposed granite, once compaction and waste are factored in.
Do I need a base layer under decomposed granite?
For pathways, decomposed granite alone directly on compacted subgrade is usually enough. For driveways or heavier use, a compacted aggregate base underneath improves stability and drainage.
Does decomposed granite need edging?
Yes, in almost all cases. As a loose or semi-loose material, decomposed granite migrates outward under foot or vehicle traffic without a physical edge to contain it.
How do you install stabilized decomposed granite?
The stabilizer, typically a resin binder, is mixed into the decomposed granite before or during placement, then compacted while workable. It cures over the following day or two into a firmer, semi-permeable surface.
How often does decomposed granite need to be refreshed?
Natural decomposed granite typically needs a top-up or re-compaction every 1 to 3 years depending on traffic and weather. Stabilized decomposed granite can last 5 or more years with minimal maintenance.
Is decomposed granite good for a driveway?
Stabilized decomposed granite can handle regular vehicle traffic reasonably well with a proper compacted base. Natural decomposed granite is better suited to pathways and patios with lighter use.
How much area does a ton of decomposed granite cover?
Roughly 100 sq ft at a 2 inch compacted depth, or about 65–70 sq ft at 3 inches, for typical decomposed granite density.
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Decomposed Granite Estimate
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Project
| Shape | — |
| Dimensions | — |
| Area | — |
| Compacted depth | — |
| Loose depth to order | — |
| Type | — |
| Compaction factor | — |
| Waste allowance | — |
Volume & weight (incl. waste)
| Cubic yards | — |
| Cubic feet | — |
| Weight | — |
| Tons (rounded up) | — |
Shopping list
| Bulk order | — |
| Bagged alternative (0.5 cu ft) | — |
| Stabilizer | — |
| Estimated cost | — |
Notes
Estimate generated by materialcalculate.com. Assumes uniform depth and standard decomposed granite densities. Confirm quantities and compaction rates with your supplier before ordering.