Gravel Calculator

What this calculator does

This calculator estimates the volume of gravel (or similar aggregate) you need to cover an area to a given depth. You enter length, width, depth, and an optional waste factor (%). Results are shown in cubic yards, cubic feet, and cubic meters so you can order or compare with supplier units.

It is useful for driveways, paths, drainage beds, and landscape projects. Homeowners and contractors use it to avoid over- or under-ordering; suppliers often quote in cubic yards (US) or cubic meters. Adding a waste factor accounts for compaction, spillage, and irregular shapes so you have a realistic amount to order.

How to use it

1. Enter Length (ft)—the longer horizontal dimension of the area to cover.
2. Enter Width (ft)—the shorter horizontal dimension (or the same unit as length).
3. Enter Depth (in)—how deep you want the gravel (e.g. 2–4 inches for a path, more for a driveway base).
4. Enter Waste % (0–50)—optional; 10% is a common default for delivery and compaction loss.
5. Read the result in cubic yards, cubic feet, and cubic meters in the Result panel.

All inputs are in the "Inputs" section; depth is in inches while length and width are in feet—the calculator converts internally.

Formulas used

• Volume = length × width × depth (in consistent units).
  Depth in inches is converted to feet by dividing by 12, so volume = length(ft) × width(ft) × (depth(in) / 12) in cubic feet.

• With waste: volume_with_waste = volume × (1 + waste% / 100).
  This gives the total volume to order so that after compaction and handling you still have enough to cover the area.

• Cubic yards = cubic feet / 27.
  One cubic yard equals 27 cubic feet; this is the standard unit for ordering in the US.

• Cubic meters = cubic feet × 0.0283168 (or from metric dimensions directly).
  Use this when ordering in metric or comparing with international suppliers.

Interpretation & examples

• Typical waste is 5–15% depending on delivery method (dumped vs. spread), compaction, and site shape; 10% is a common default. For irregular areas or thick layers, use a higher waste factor.
• Example 1: 10 ft × 10 ft × 4 in with 10% waste → about 1.36 cubic yards (~1.04 m³). Enough for a small patio or path.
• Example 2: 20 ft × 12 ft × 3 in, 15% waste → volume ≈ 20 × 12 × (3/12) = 60 ft³; with waste 69 ft³ ≈ 2.56 cubic yards. Useful for a driveway section.
• Example 3: 30 ft × 20 ft × 6 in, 10% waste → 30 × 20 × 0.5 = 300 ft³; with waste 330 ft³ ≈ 12.2 cubic yards. Order 12–13 cubic yards for a large project.

History & background

Gravel and aggregate have been sold by volume for decades. In the US, cubic yards are the standard unit for bulk delivery; in many other countries, cubic meters are used. Waste factors come from contractor and landscape practice—aggregate compacts when driven or walked on, and some material is lost during dumping and spreading. The formulas are standard geometry; the main skill is measuring the area accurately and choosing a realistic depth and waste percentage for your project type.

Limitations & safety notes

• Estimate only. Actual need depends on compaction, stone size (e.g. 3/4" vs. pea gravel), and site shape. Sloped or curved areas may need more material.
• Order slightly more for critical projects (e.g. drainage or structural base) and confirm with your supplier. Many suppliers have minimum delivery amounts.
• Depth and dimensions should reflect the finished area; add extra if you are excavating and backfilling. This tool does not replace a site visit or professional estimate for large or engineered projects.