Bags of Decomposed Granite for a 4x40 Walkway
How many bags of decomposed granite for a 4x40 walkway: at 3 inches deep you need about 40.0 cubic feet, which is 80 bags of the common 0.5 cubic foot size. If your store sells decomposed granite in 50-pound bags instead, figure about 80 bags, since decomposed granite weighs roughly 100 pounds per cubic foot.
Volume and tonnage calculator →Bag count by depth
| Depth | Cubic feet | 0.5 cu ft bags | 50 lb bags (approx.) |
|---|---|---|---|
| 1 in | 13.3 | 27 | 27 |
| 2 in | 26.7 | 54 | 54 |
| 3 in | 40.0 | 80 | 80 |
| 4 in | 53.3 | 107 | 107 |
How to figure it
- Area: 4 × 40 = 160 sq ft.
- Volume: 160 × (3 ÷ 12) = 40.0 cu ft.
- Bags: 40.0 ÷ 0.5 = 80 bags (round up).
Bags or bulk?
A cubic yard is 27 cubic feet, so 40.0 cubic feet is 1.48 yards, about 2.0 tons. Past about a yard, bulk is usually less work and often less money. Compare the bag price × 80 against a bulk quote for 2.2 tons delivered.
About decomposed granite
DG should be laid in thin lifts, wetted and compacted. Loose DG at a deep depth stays soft and tracks onto shoes.
Laying it down for a walkway
- Dig and level. Remove sod and set the base slightly below the surrounding grade.
- Edge it. Steel, plastic or stone edging keeps material in place.
- Spread in layers. Rake to depth, then tamp or wet and compact.
- Buy a few extra. Grab 5 to 10 percent more bags for settling and touch-ups.
The volume and tonnage calculator handles other sizes and depths.
Where decomposed granite fits
Good uses:
- Garden paths and patios with a natural look
- Around trees and in xeriscape designs
- Stabilized DG for accessible paths
Think twice for:
- 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 15x30 area at 4 inches takes about 7.5 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.
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
Questions people ask
How many bags of decomposed granite for a 4x40 walkway?
About 80 bags of 0.5 cubic feet at 3 inches deep.
How many 50 lb bags of decomposed granite for 4x40?
About 80 bags at 3 inches.
How many 0.5 cubic foot bags are in a cubic yard?
54 bags.
How many cubic feet is a 4x40 walkway at 3 inches?
About 40.0 cubic feet.
When does bulk make more sense?
Usually once the job passes about a cubic yard, or when you would need more than a few car trips.
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
- Bags of Decomposed Granite for a 4x25 Walkway
- Bags of Decomposed Granite for a 4x30 Walkway
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