Calculate Cubic Yards of Gravel: Formula & Guide

This calculator determines the volume of gravel needed for a project in cubic yards. You enter the length, width, and depth of the area to be filled, and it returns the required volume in cubic yards (and optionally in cubic feet and tons). The calculation uses the standard formula: Volume (cubic yards) = (Length × Width × Depth) / 27, since there are 27 cubic feet in one cubic yard.

Formula

The formula for calculating cubic yards of gravel is straightforward:

Volume (yd³) = (Length (ft) × Width (ft) × Depth (ft)) / 27

Where:

• Length – the longest horizontal dimension of the area, measured in feet (ft).
• Width – the horizontal dimension perpendicular to length, measured in feet (ft).
• Depth – how thick the gravel layer will be, measured in feet (ft). If you measure in inches, divide by 12 to convert to feet.
• 27 – the number of cubic feet in one cubic yard (3 ft × 3 ft × 3 ft = 27 ft³).

If your measurements are in meters, the equivalent formula is: Volume (m³) = Length (m) × Width (m) × Depth (m), then convert to cubic yards by multiplying by 1.30795 (since 1 m³ = 1.30795 yd³).

Worked Example

Using the default values from the calculator (Length = 10 ft, Width = 5 ft, Depth = 4 in):

1. Convert depth from inches to feet: 4 in ÷ 12 = 0.333 ft
2. Calculate volume in cubic feet: 10 ft × 5 ft × 0.333 ft = 16.67 ft³
3. Convert to cubic yards: 16.67 ft³ ÷ 27 = 0.62 yd³

The calculator rounds to two decimals, giving 0.62 cubic yards. This is the volume of gravel you would need to fill a 10×5 foot area to a depth of 4 inches.

Why Use Cubic Yards?

Gravel is sold by the cubic yard in most regions, especially in the United States. Suppliers typically deliver gravel in bulk by the cubic yard, and the price is quoted per cubic yard. Knowing your cubic yardage lets you order the right amount without over- or under-ordering, which saves money and avoids project delays.

For smaller projects, you might buy gravel in bags (often 0.5 cubic feet each), but for anything larger than a few square feet, bulk delivery is more practical and cost-effective. A cubic yard of gravel covers about 100 square feet at 3 inches deep, or 81 square feet at 4 inches deep.

How to Measure Your Project Area

Accurate measurements are critical for estimating gravel volume. Follow these steps:

• Rectangular areas: Measure length and width in feet (or meters). Multiply them to get square footage.
• Circular areas: Measure the radius (half the diameter) in feet. Area = Ï€ × radius². For a 10-foot diameter circle, radius = 5 ft, area = 3.1416 × 25 = 78.54 ft².
• Irregular shapes: Break the area into rectangles, triangles, or circles, calculate each, and sum them. For a triangle, area = 0.5 × base × height.
• Depth: Decide how thick the gravel layer should be. Common depths: 2–3 inches for walkways, 4–6 inches for driveways, 6–8 inches for base layers under pavers.

Always measure in the same units. If you measure length in feet, width must be in feet, and depth in feet (or convert inches to feet). Mixing units is the most common error in gravel calculations.

Common Mistakes and How to Avoid Them

Several pitfalls can lead to incorrect gravel estimates:

• Unit mix-ups: Using inches for depth but feet for length without converting. Always convert everything to feet first.
• Forgetting to divide by 27: The result in cubic feet must be divided by 27 to get cubic yards. Many people skip this and order 27 times too much gravel.
• Ignoring compaction: Gravel compacts when rolled or tamped, reducing its volume by about 10–20%. If you are compacting, order 10–20% extra.
• Not accounting for waste: Spills, uneven ground, and mistakes can waste material. Adding 5–10% extra is standard practice.
• Assuming all gravel is the same: Different gravel types have different densities, affecting weight per cubic yard. The calculator’s ton estimate uses an average density of 1.4 tons per cubic yard, but actual values range from 1.2 to 1.7 tons per cubic yard.

How to Choose the Right Gravel Type

The type of gravel you choose affects both appearance and function. Common options include:

• Pea gravel: Small, rounded stones (about 3/8 inch). Good for walkways, playgrounds, and drainage. Comfortable to walk on but shifts easily.
• Crushed stone: Angular pieces that lock together. Available in sizes from 1/4 inch to several inches. Ideal for driveways and base layers because it compacts well.
• River rock: Larger, smooth stones. Used for decorative purposes and drainage, but not suitable for driveways due to poor compaction.
• Decomposed granite: Fine, sandy material that compacts into a firm surface. Good for paths and patios.

For driveways, a common practice is to use a larger crushed stone (e.g., #3 or #4) as a base, then a smaller crushed stone (e.g., #57) on top. For walkways, 1–2 inches of pea gravel or decomposed granite is typical.

Cost Considerations

Gravel prices vary by region, type, and delivery method. On average, bulk gravel costs between $15 and $75 per cubic yard, with crushed stone on the lower end and decorative river rock on the higher end. Delivery fees are often separate, and some suppliers have minimum order quantities.

To estimate your total cost, multiply the cubic yards by the per-yard price, then add delivery. For example, 2 cubic yards at $30 per yard = $60 plus delivery. Bagged gravel is more expensive per cubic yard (often $100–$200 per cubic yard equivalent) but is convenient for small projects.

Always ask the supplier for the exact density of the gravel you plan to order, as this affects how many tons you need. A cubic yard of gravel weighs roughly 2,800 pounds (1.4 tons), but this varies.

Safety and Preparation

Working with gravel involves physical labor and potential hazards. Keep these safety tips in mind:

• Lifting: Gravel is heavy. Use a wheelbarrow or shovel, and lift with your legs to avoid back injuries.
• Dust: Fine gravel dust can irritate lungs. Wear a dust mask when handling dry gravel, especially in enclosed spaces.
• Footwear: Wear sturdy boots with good traction to prevent slips on loose stones.
• Ground prep: Clear the area of vegetation and debris before laying gravel. For driveways, a geotextile fabric underneath prevents gravel from sinking into the soil.
• Edging: Install edging (wood, metal, or plastic) to keep gravel contained, especially on slopes.

Frequently Asked Questions

How many square feet does a cubic yard of gravel cover?

It depends on depth. A cubic yard covers 324 square feet at 1 inch deep, 162 square feet at 2 inches, 108 square feet at 3 inches, and 81 square feet at 4 inches. Use the formula: coverage (sq ft) = 27 / depth (ft).

How do I calculate gravel for a circular area?

Measure the radius (half the diameter) in feet, square it, multiply by π (3.1416) to get the area, then multiply by the depth in feet and divide by 27. For a 10-foot diameter circle at 4 inches deep: area = 78.54 sq ft, volume = 78.54 × 0.333 / 27 = 0.97 cubic yards.

Should I order extra gravel? How much?

Yes, it’s wise to order 5–10% extra to account for compaction, waste, and uneven surfaces. If you’re compacting the gravel, add 10–20% more because compaction reduces volume.

How many tons is a cubic yard of gravel?

Most gravel weighs between 1.2 and 1.7 tons per cubic yard, with an average of about 1.4 tons. The calculator uses 1.4 tons per cubic yard for its estimate. Check with your supplier for the exact density of the specific gravel.

Can I use this calculator for other materials like sand or soil?

Yes, the volume calculation is the same for any bulk material. However, the weight estimate (tons) will differ because each material has a different density. Sand is typically 1.2–1.4 tons per cubic yard, while topsoil is about 0.9–1.1 tons per cubic yard.

What depth of gravel do I need for a driveway?

For a residential driveway, a total depth of 4–6 inches of gravel is recommended. This is usually applied in two layers: a 4-inch base of larger crushed stone (e.g., #3) and a 2-inch top layer of smaller stone (e.g., #57). For heavy vehicles, increase to 8–10 inches.

Related

• Cubic Yard to Cubic Feet: The Simple Conversion
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in l | Length | ft | 10 | 0
in w | Width | ft | 5 | 0
in d | Depth | in | 4 | 0
out cy | Cubic Yards | yd³ | (l * w * (d / 12)) / 27 | 2
out cf | Cubic Feet | ft³ | l * w * (d / 12) | 2
out tons | Estimated Tons | tons | ((l * w * (d / 12)) / 27) * 1.4 | 2