River Rock Calculator – Estimate Volume, Weight, and Tons

Last updated: 07 Sep 2025 | Author: Brij | Review By: Irshad

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Use our River Rock Calculator to estimate how much river rock you need for landscaping projects. Calculate volume, weight, and tons of river rock based on area, depth, and coverage density.

Area Length:

Area Width:

Depth of Rock Layer:

Rock Density (optional):

Average river rock density: 100 lbs/ft³

Waste Factor:

Extra material for waste & settling

River Rock Calculation Results

Output Unit:

Area to Cover:

sq ft

Volume of River Rock Needed:

cubic ft

Total Weight of River Rock:

lbs

Number of Tons of River Rock:

tons

River Rock Information

River Rock Characteristics:
- Naturally smooth, rounded stones
- Typically ¾" to 1½" in diameter
- Average density: 100 lbs per cubic foot
- Excellent for drainage and landscaping
- Available in various natural colors

Coverage Guidelines:
- For landscaping: 2-3 inch depth
- For drainage applications: 4-6 inch depth
- 1 ton covers approx. 80-100 sq ft at 2" depth
- 1 cubic yard covers approx. 100-120 sq ft at 2" depth
- Add 10-20% for waste and settling

If you are planning a landscaping project that involves river rock, gravel, or decorative stones, it is important to calculate the right amount of material. Ordering too little may leave gaps, while ordering too much increases costs. A River Rock Calculator helps you estimate the volume, weight, and tons of river rock needed for your project based on area and depth.

Step 1: Calculate Area to Cover

The area is simply the product of length and width.

$\text{Area} = \text{Length} \times \text{Width}$

Step 2: Calculate Volume of River Rock

The volume is the product of area and depth (thickness). Depth must be converted into feet (if input is in inches).

$\text{Volume} = \text{Area} \times \text{Depth}$

Step 3: Convert Volume to Weight

The weight depends on the density of river rock. On average, river rock weighs about 100 lbs per cubic foot (or 1600 kg/m³).

$\text{Weight} = \text{Volume} \times \text{Density}$

Step 4: Convert Weight to Tons

Since 1 ton = 2000 lbs, we can convert easily:

$\text{Tons} = \frac{\text{Weight (lbs)}}{2000}$

Example Calculation

Suppose you want to cover a garden bed of 20 ft length, 10 ft width, with a 3-inch depth of river rock.

Area

$\text{Area} = 20 \times 10 = 200 \ \text{sq ft}$

Depth in feet

$3 \ \text{inches} = \frac{3}{12} = 0.25 \ \text{ft}$

Volume

$\text{Volume} = 200 \times 0.25 = 50 \ \text{cubic ft}$

Weight

$\text{Weight} = 50 \times 100 = 5000 \ \text{lbs}$

Tons

$\text{Tons} = \frac{5000}{2000} = 2.5 \ \text{tons}$

Final Answer: You will need 2.5 tons of river rock for this project.

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River Rock Calculator – Estimate Volume, Weight, and Tons

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