Bags of River Rock for a 3x50 Walkway
How many bags of river rock for a 3x50 walkway: at 3 inches deep you need about 37.5 cubic feet, which is 75 bags of the common 0.5 cubic foot size. If your store sells river rock in 50-pound bags instead, figure about 75 bags, since river rock 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 | 12.5 | 25 | 25 |
| 2 in | 25.0 | 50 | 50 |
| 3 in | 37.5 | 75 | 75 |
| 4 in | 50.0 | 100 | 100 |
How to figure it
- Area: 3 × 50 = 150 sq ft.
- Volume: 150 × (3 ÷ 12) = 37.5 cu ft.
- Bags: 37.5 ÷ 0.5 = 75 bags (round up).
Bags or bulk?
A cubic yard is 27 cubic feet, so 37.5 cubic feet is 1.39 yards, about 1.9 tons. Past about a yard, bulk is usually less work and often less money. Compare the bag price × 75 against a bulk quote for 2.1 tons delivered.
About river rock
River rock is smooth, water-worn stone sold in sizes from about 3/4 inch to several inches. Larger sizes cover fewer square feet per ton at the same depth because the voids between stones are bigger.
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 rake smooth; rounded stone will not 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.
When to choose river rock
Good uses:
- Dry creek beds and drainage swales
- Decorative borders and planting beds
- Around downspouts to stop splash erosion
Think twice for:
- Walking surfaces
- Driveways
- Bases under slabs or pavers
Quick reference numbers
- Per inch over 100 sq ft: about 0.42 tons of river rock (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.2 tons.
- Another size for comparison: a 10x20 area at 2 inches takes about 1.7 tons.
- Weight used here: about 1.35 tons per cubic yard.
Mistakes that throw off the order
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
- Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
Questions people ask
How many bags of river rock for a 3x50 walkway?
About 75 bags of 0.5 cubic feet at 3 inches deep.
How many 50 lb bags of river rock for 3x50?
About 75 bags at 3 inches.
How many 0.5 cubic foot bags are in a cubic yard?
54 bags.
How many cubic feet is a 3x50 walkway at 3 inches?
About 37.5 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
- How Much Does a Ton of River Rock Cover?
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Much Does a Ton of Gravel Cover? Depth Chart
- Bags of River Rock for a 3x30 Walkway
- Bags of River Rock for a 3x40 Walkway
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