How Much River Rock for a 3x40 Walkway?
How much river rock for a 3x40 walkway is a quick volume problem. 120 square feet at 3 inches comes to 1.11 cubic yards. River rock usually weighs about 1.25 to 1.45 tons per cubic yard, so plan on roughly 1.5 tons.
Volume and tonnage calculator →The math for a 3x40 walkway
- Area: 3 × 40 = 120 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic feet: 120 × 0.250 = 30.0 cu ft.
- Cubic yards: ÷ 27 = 1.11 yd³.
- Tons: × 1.35 = 1.5 tons.
The volume and tonnage calculator does this for any size.
River rock needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 2 in | 0.74 | 1.0 | 1.1 |
| 3 in | 1.11 | 1.5 | 1.7 |
| 4 in | 1.48 | 2.0 | 2.2 |
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. Ask your supplier for their own tons-per-yard figure, since stone source and moisture shift it.
Preparing the walkway
Dig the path a few inches below grade, compact the bottom, add fabric if needed and install edging on both sides so the material stays on the walk. This walkway sees foot traffic, so match the depth to that load rather than to the minimum.
Ordering tips
- Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
- Delivery size. 1.7 tons fits in a single typical dump truck load; small loads may carry a delivery fee. See how many tons of gravel in a dump truck.
- Bulk vs bags. At this size bulk delivery is usually the practical choice.
- Where it drops. Have the truck dump as close to the walkway as firm ground allows.
Where river rock fits
Works well for:
- Dry creek beds and drainage swales
- Decorative borders and planting beds
- Around downspouts to stop splash erosion
Poor fit 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 8x16 area at 4 inches takes about 2.1 tons.
- Weight used here: about 1.35 tons per cubic yard.
Mistakes that throw off the order
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
Questions people ask
How many tons of river rock for a 3x40 walkway?
About 1.5 tons at 3 inches deep, or 1.7 tons with 10 percent extra.
How many cubic yards is a 3x40 walkway at 3 inches?
About 1.11 cubic yards.
How much does a cubic yard of river rock weigh?
Usually around 1.25 to 1.45 tons, depending on stone size, fines and moisture.
How deep should river rock be for a walkway?
The table above shows 2 to 4 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.
How many square feet is 3x40?
120 square feet.
Related guides
- How Much Does a Ton of River Rock Cover?
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Does a Ton of Gravel Cover? Depth Chart
- How Much River Rock for a 3x25 Walkway?
- How Much River Rock for a 3x30 Walkway?
As an Amazon Associate, AsphaltTons.com earns from qualifying purchases. Product links below are sponsored.