How Much River Rock Do I Need? Tons and Bags by Area
Multiply the area by the depth to get the volume, then convert to tons. 100 sq ft of river rock 2 inches deep takes 0.62 cubic yards, about 0.80 tons, or 34 bags of 0.5 cu ft. One ton covers roughly 125 sq ft at 2 inches. The gravel calculator has a river rock option for any area.
River rock by area and depth
Tons at about 2,600 lb per cubic yard. The bag column is 0.5 cu ft bags at 2 inches deep.
| Area | 2 in deep | 3 in deep | 4 in deep | Bags (2 in) |
|---|---|---|---|---|
| 50 sq ft | 0.40 t · 0.31 yd³ | 0.60 t · 0.46 yd³ | 0.80 t · 0.62 yd³ | 17 |
| 100 sq ft | 0.80 t · 0.62 yd³ | 1.20 t · 0.93 yd³ | 1.60 t · 1.23 yd³ | 34 |
| 200 sq ft | 1.60 t · 1.23 yd³ | 2.41 t · 1.85 yd³ | 3.21 t · 2.47 yd³ | 67 |
| 300 sq ft | 2.41 t · 1.85 yd³ | 3.61 t · 2.78 yd³ | 4.81 t · 3.70 yd³ | 100 |
| 500 sq ft | 4.01 t · 3.09 yd³ | 6.02 t · 4.63 yd³ | 8.02 t · 6.17 yd³ | 167 |
| 1,000 sq ft | 8.02 t · 6.17 yd³ | 12.04 t · 9.26 yd³ | 16.05 t · 12.35 yd³ | 334 |
How deep to lay river rock
A good rule is about twice the size of the stones, so the ground doesn't show between them:
- 3/4 to 1 1/2 inch rock: 2 inches deep. Common for beds and paths.
- 1 to 3 inch rock: 3 inches deep. Good for dry creek beds and drainage areas.
- 3 to 5 inch rock: 4 to 6 inches deep, usually for borders and creek bed edges.
Worked example: 4 × 25 ft side yard strip
- Area: 4 × 25 = 100 sq ft
- Volume at 2 inches: 100 × 2 ÷ 12 = 16.7 cu ft = 0.62 cu yd
- Weight: 0.62 × 2,600 lb = 1,605 lb ≈ 0.80 tons
- Or in bags: 16.7 ÷ 0.5 = 34 bags
Bags or bulk?
Bags are easy for small jobs, but at around 50 lb each they add up fast in cost and carrying. From about half a ton up, bulk from a landscape yard is usually much cheaper. A half-ton pickup can safely carry about half a cubic yard of rock, so plan on delivery or a trailer for more.
Before you spread it
- Lay landscape fabric to keep weeds down and stop the rock sinking into the soil.
- Edge the area with steel, stone or plastic edging so rock doesn't wander into the lawn.
- Slope away from the house when river rock replaces mulch along the foundation.
Frequently asked questions
How much river rock do I need for 100 square feet?
At 2 inches deep, 0.62 cubic yards: about 0.80 tons or 34 bags of 0.5 cu ft. At 3 inches, 1.20 tons.
How much river rock do I need for 200 square feet?
1.60 tons at 2 inches deep, or 2.41 tons at 3 inches.
How much river rock do I need for 300 square feet?
2.41 tons at 2 inches deep, or 3.61 tons at 3 inches. At that size, bulk delivery is far cheaper than 100 bags.
How many square feet does a ton of river rock cover?
About 125 sq ft at 2 inches deep, 83 sq ft at 3 inches and 62 sq ft at 4 inches.
How much does a yard of river rock weigh?
About 2,400 to 2,900 lb, so roughly 1.3 tons. Larger, rounder rock has more gaps and weighs a little less per yard.