Geneva Rock Calculator: Weight & Volume

The Geneva Rock calculator estimates the weight and volume of rock, sand, and gravel needed for a landscaping or construction project. You enter the length, width, and depth of the area, plus the material type, and it returns the volume in cubic yards and the weight in tons. This gives you a quick, reliable starting point for ordering aggregate from a quarry or supplier.

Formula

The core formula is straightforward: Volume (cubic yards) = (Length × Width × Depth) ÷ 27, where depth is converted from inches to feet first. Then Weight (tons) = Volume × Material Density (tons per cubic yard). The density values are approximate averages for common materials:

• Crushed rock: ~1.4 tons per cubic yard
• Sand: ~1.2 tons per cubic yard
• Gravel: ~1.35 tons per cubic yard
• Topsoil: ~1.1 tons per cubic yard

These are dry, loose densities. Wet or compacted material can weigh 10–20% more.

Worked Example

Using the defaults: Length = 20 ft, Width = 10 ft, Depth = 4 in, Material = Crushed Rock.

1. Convert depth to feet: 4 in ÷ 12 = 0.333 ft
2. Volume in cubic feet: 20 × 10 × 0.333 = 66.7 ft³
3. Convert to cubic yards: 66.7 ÷ 27 = 2.47 yd³
4. Weight: 2.47 × 1.4 = 3.46 tons

The calculator rounds to 3.46 tons and 2.47 cubic yards. Always order about 10% extra to account for compaction and uneven ground.

How to Choose the Right Material

Your project dictates the material. For a driveway or base, crushed rock (often called crushed stone) is best because it interlocks and compacts well. For a paver base, use a finer crushed rock. Sand is used for leveling pavers or in play areas. Gravel (rounded, not crushed) is good for drainage and decorative paths. Topsoil is for garden beds. Each has a different density, so using the correct selection in the calculator matters.

Common Mistakes and How to Avoid Them

• Mixing units: Always measure length and width in feet, depth in inches. If you measure in meters, convert first (1 m = 3.28 ft).
• Forgetting compaction: Loose rock compacts down by about 10–15%. If you need a 4-inch compacted base, you should order 4.5–5 inches of loose material.
• Rounding too early: Do all calculations with full precision, then round at the end.
• Ignoring moisture: Wet sand or soil weighs more. If it has rained recently, add a few percent.

Limits of the Formula

This calculator gives an estimate, not an exact order. Actual weight depends on the specific rock type (e.g., granite vs. limestone), moisture content, and how the supplier loads it. Different suppliers may use slightly different densities. Always confirm with your local supplier—they know the exact weight per yard for their material. Also, the formula assumes a uniform depth. If your area has slopes or varying depths, divide it into sections and calculate each separately.

Cost Considerations (Not Included)

The calculator does not include price because costs vary widely by region, material, and delivery distance. As a rough guide, crushed rock and gravel are typically the cheapest, while decorative stones and specialty topsoil cost more. Delivery fees often depend on distance and quantity. To estimate cost, multiply the tons by the per-ton price from your supplier, plus any delivery charge.

Safety and Handling

When working with rock and gravel, wear gloves and safety glasses. Lifting heavy stones can strain your back—use proper lifting technique or a wheelbarrow. If you’re having material delivered, keep children and pets away from the drop zone. For large projects, consider renting equipment like a skid steer. Never stand under a raised dump truck bed.

Frequently Asked Questions

How many cubic yards are in a ton? It depends on the material. For crushed rock, about 0.71 cubic yards per ton (1 ÷ 1.4). For sand, about 0.83 cubic yards per ton. Use the calculator to convert precisely.

What is the difference between a cubic yard and a ton? A cubic yard is a volume measure (3 ft × 3 ft × 3 ft). A ton is a weight measure (2,000 pounds). The relationship is density—how much a cubic yard of that material weighs.

How deep should a gravel driveway be? For a residential driveway, a 4–6 inch compacted layer of crushed rock is typical. For heavy vehicles, go deeper. The calculator can show you how much that is.

Can I use this calculator for mulch or soil? Yes, but the density values are for rock and sand. Mulch is much lighter (~0.2–0.4 tons per yard), so the weight result would be wrong. Use a mulch-specific calculator for that.

Why does my order come out different from the calculator? Suppliers may use different densities, or they may round up to the nearest half yard. Also, if your area is not perfectly flat, your actual volume will differ.

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in l | Length | ft | 20 | 0
in w | Width | ft | 10 | 0
in d | Depth | in | 4 | 0
sel m | Material | Crushed Rock=1.4, Sand=1.2, Gravel=1.35, Topsoil=1.1
out tons | Estimated weight | tons | (l * w * (d / 12)) * m / 27 * 1.35 | 2
out cy | Volume | cubic yards | (l * w * (d / 12)) / 27 | 2