How Much Decomposed Granite for 400 Square Feet?
How much decomposed granite for 400 square feet depends on depth. At 3 inches you need about 3.70 cubic yards, roughly 5.0 tons at 1.35 tons per yard. Each inch of depth over 400 square feet adds about 1.23 yards.
Volume and tonnage calculator →Decomposed granite for 400 sq ft by depth
| Depth | Cubic yards | Tons | Tons +10% |
|---|---|---|---|
| 2 in | 2.47 | 3.3 | 3.7 |
| 3 in | 3.70 | 5.0 | 5.5 |
| 4 in | 4.94 | 6.7 | 7.3 |
Working it out
- 400 sq ft × (3 ÷ 12) ft = 100.0 cubic feet.
- ÷ 27 = 3.70 cubic yards.
- × 1.35 tons per yard = 5.0 tons.
About decomposed granite
Decomposed granite (DG) is weathered granite broken into small particles and fines. It packs into a firm, natural-looking path surface, and stabilized versions include a binder. Expect the weight to fall in the range of 1.25 to 1.45 tons per yard.
Getting the order right
- Measure odd shapes in pieces. Split curves and L-shapes into rectangles and add them.
- Add a margin. About 10 percent covers compaction and low spots.
- Bulk or bags. Bulk delivery is the practical choice here.
- Prep first. Remove sod, compact the subgrade and set edging before the stone arrives.
Use the volume and tonnage calculator for any other size.
Good and poor uses for decomposed granite
Works well for:
- Garden paths and patios with a natural look
- Around trees and in xeriscape designs
- Stabilized DG for accessible paths
Less suited to:
- Steep grades without a stabilizer
- Areas right outside doors, since fines track in
- Driveways with heavy turning traffic
Quick reference numbers
- Per inch over 100 sq ft: about 0.42 tons of decomposed granite (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.2 tons.
- Another size for comparison: a 10x20 area at 4 inches takes about 3.3 tons.
- Weight used here: about 1.35 tons per cubic yard.
Mistakes that throw off the order
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
Questions people ask
How many tons of decomposed granite for 400 square feet?
About 5.0 tons at 3 inches deep.
How many cubic yards of decomposed granite for 400 square feet?
About 3.70 yards at 3 inches.
How much decomposed granite for 400 square feet at 2 inches?
About 3.3 tons, or 2.47 cubic yards.
How much does a yard of decomposed granite weigh?
About 1.25 to 1.45 tons.
Should I add extra?
Yes, about 10 percent is a common allowance.
Related guides
- Crushed Stone vs Gravel: Differences and Best Uses
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Much Does a Ton of Gravel Cover? Depth Chart
- How Much Decomposed Granite for 250 Square Feet?
- How Much Decomposed Granite for 300 Square Feet?
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