How Much Decomposed Granite for a 20 Foot Circle?
Round areas such as fire pit patios, tree rings and seating circles use less stone than a square of the same width. A 20-foot circle is about 314.2 square feet; at 3 inches that is 3.9 tons of decomposed granite.
Volume and tonnage calculator →The math
- Area: 314.2 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic yards: 314.2 × 0.250 ÷ 27 = 2.91 yd³.
- Tons: × about 1.35 tons per yard = 3.9 tons.
The gravel calculator does this for any size.
Related: How Much Gravel for a 20 Foot Circle?
Decomposed granite needed by depth
| Depth | Cubic yards | Tons of decomposed granite | Tons +10% |
|---|---|---|---|
| 2 in | 1.94 | 2.6 | 2.9 |
| 3 in | 2.91 | 3.9 | 4.3 |
| 4 in | 3.88 | 5.2 | 5.8 |
| 6 in | 5.82 | 7.9 | 8.6 |
Using a circle of stone
Circles show up around fire pits, under swing sets, around trees and as seating areas. Steel or paver edging keeps the round shape crisp and holds loose stone in place. For a fire pit area, keep combustibles well away and check local burn rules.
Related: How Much Decomposed Granite for a 6 Foot Circle?
Buying the stone
Small dump trucks commonly carry around 5 to 10 tons and tri-axles more, but loads vary by truck and state, so ask the yard what fits in one trip. Decomposed granite packs into a firm, natural path when wetted and compacted in thin lifts. Round up by about 10 percent for compaction and uneven ground.
Tools for the job
A flat shovel, a steel rake, a wheelbarrow and a rented plate compactor cover most residential pads. A landscape rake or the back of a rake levels the top layer, and a long straightedge or a level string shows high and low spots before the final pass.
Common mistakes
The most frequent problem is ordering for the finished depth without allowing for compaction, which can shrink a loose layer by 10 to 20 percent. Another is skipping fabric on soft soil and watching the stone vanish into the mud over the first wet season. Spreading everything in one thick layer instead of compacted lifts also leaves a soft, rutted surface.
Questions people ask
How many tons of decomposed granite for a 20 ft circle?
About 3.9 tons at 3 inches deep.
How many square feet is a 20 foot circle?
About 314.2 square feet.
How many tons of decomposed granite are in a cubic yard?
Roughly 1.35 tons for planning, but suppliers vary with stone size and moisture.
Do I need to compact it?
Yes for anything that carries weight. Compact in lifts of a few inches with a plate compactor.
Related guides
- Gravel for a Fire Pit Area: Best Types and Depth
- How Much Does a Ton of Gravel Cover? Depth Chart
- Tons to Cubic Yards for Gravel: Conversion Chart
- Crushed Stone vs Gravel: Differences and Best Uses
- Geotextile Fabric for Driveways: Woven vs Nonwoven and How Much You Need
- Compacting a Driveway Gravel Base in Lifts
- How Much Pea Gravel for a 20 Foot Circle?
- How Much River Rock for a 20 Foot Circle?
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