River Rock Calculator
Enter the area and depth of your bed to estimate how much river rock you need in cubic yards and tons, plus the number of bags.
Results
- Volume needed
- 1.23 cu yd
- With 10% waste
- 1.36 cu yd
- Cubic feet
- 33.33 cu ft
- Cubic meters
- 0.94 m³
- Estimated weight
- 1.9 tons
- 0.5 cu ft bags
- 74 bags
Estimates only. Round up and buy a little extra to account for waste, spills, and breakage.
Enter the area and depth of your bed to estimate how much river rock you need in cubic yards and tons, plus the number of bags.
How to use the river rock calculator
- Enter the shape.
- Enter the length in ft.
- Enter the width in ft.
- Enter the depth in in.
- Enter the waste factor in %.
- Optionally add a price to estimate the total project cost.
- Read your quantities instantly — no sign-up, and you can print the estimate to take to the supplier.
Worked example
Inputs
- Shape
- Rectangle / Square
- Length
- 20 ft
- Width
- 10 ft
- Depth
- 2 in
- Waste factor
- 10 %
Results
- Volume needed
- 1.23 cu yd
- With 10% waste
- 1.36 cu yd
- Cubic feet
- 33.33 cu ft
- Cubic meters
- 0.94 m³
- Estimated weight
- 1.9 tons
- 0.5 cu ft bags
- 74 bags
Using the example values above, the river rock calculator returns 1.23 cu yd (volume needed). Change any field to match your own project and the numbers update instantly.
How much extra should I order?
Always order a little extra. A 5% waste factor suits simple, square projects; 10% is right for most jobs; bump it to 15–20% for irregular shapes, diagonal patterns, or uneven ground. Running short almost always costs more than the leftover material.
Formula
Volume (cu ft) = area × depth ÷ 12. Cubic yards = cu ft ÷ 27. Waste-adjusted = volume × (1 + waste%).
Frequently asked questions
- How deep should river rock be?
- Spread river rock 2–3 inches deep for ground cover and 3–4 inches over a drainage trench or weed barrier.
- How many tons of river rock do I need?
- Multiply the area by the depth in feet to get cubic feet, divide by 27 for cubic yards, then multiply by about 1.4 to get tons.
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