Cubic Yard Calculator Gravel: Formula, Cost & Coverage

A cubic yard calculator for gravel works out the volume of gravel you need in cubic yards when you enter the length, width, and depth of the area to be filled. You get the cubic yardage, which you can then multiply by the gravel density (about 1.4 tons per cubic yard for typical crushed stone) to estimate the total weight and cost. The calculator below does the volume math for you, so you only need to measure your project area and choose a depth.

Formula

The basic formula for cubic yards of gravel is:

Cubic Yards = (Length × Width × Depth) ÷ 27

Where:

• Length – the longer horizontal measurement of the area, in feet (ft)
• Width – the shorter horizontal measurement, in feet (ft)
• Depth – how thick you want the gravel layer, in inches (in), converted to feet by dividing by 12
• 27 – the number of cubic feet in one cubic yard (3 ft × 3 ft × 3 ft)

If you measure in meters, the equivalent is: Cubic yards = (Length m × Width m × Depth m) × 1.30795, because 1 cubic meter = 1.30795 cubic yards. Most gravel suppliers in the US sell by the cubic yard, so this formula is the standard for ordering.

Worked Example

Using the calculator defaults: length = 10 ft, width = 5 ft, depth = 4 in.

1. Convert depth to feet: 4 in ÷ 12 = 0.3333 ft
2. Calculate volume in cubic feet: 10 × 5 × 0.3333 = 16.665 ft³
3. Convert to cubic yards: 16.665 ÷ 27 = 0.617 yd³
4. Estimate weight: 0.617 yd³ × 1.4 tons/yd³ = 0.864 tons (about 1,728 lb)

The calculator rounds to 0.62 cubic yards and 0.86 tons. If you order from a supplier, you would likely order 1 cubic yard because most sell in whole or half-yard increments.

How to Measure Your Area Correctly

Accurate measurements are the difference between a smooth project and running out of gravel mid-job. Follow these steps:

• For a rectangular area (patio base, walkway, flower bed), measure length and width at the widest points. Use a tape measure, not a wheel measurer, for areas under 50 ft.
• For an irregular shape (circular fire pit, curved path), break it into rectangles and triangles. For a circle, measure the diameter, divide by 2 for radius, then use: Area = Ï€ × r². Convert that area to square feet, then multiply by depth.
• For a triangular area (corner garden), multiply base × height ÷ 2 to get square footage.
• Decide on depth based on use: 2–3 inches for a walkway, 4–6 inches for a driveway (with compacted base), 3–4 inches for a drainage trench.
• Add 5–10% extra for compaction and uneven ground. Gravel compacts by about 10–15% under a plate compactor, so if you need 1 yd³ after compaction, order 1.1–1.15 yd³.

Always measure in the same unit. Mixing feet and inches is the most common error. Convert everything to feet before calculating.

Common Gravel Types and Their Densities

Not all gravel weighs the same. The density (weight per cubic yard) affects how many tons you need and how much it costs. Typical dry densities:

• Pea gravel (small, round, 3/8-inch): ~1.4 tons/yd³
• Crushed stone #57 (angular, 1-inch): ~1.4 tons/yd³
• Crushed stone #3 (larger, 1–2 inches): ~1.35 tons/yd³
• Bank gravel (mixed sand and stone): ~1.5 tons/yd³
• Decomposed granite (fine, dust-like): ~1.3 tons/yd³
• Loose gravel, dry: ~1.25 tons/yd³; wet gravel can weigh 10–15% more

These are approximate. Check with your local supplier for the exact weight of the specific material you order. The calculator uses 1.4 tons/yd³ as a middle-ground default, which works for most crushed stone.

How to Convert Cubic Yards to Tons and Cost

Suppliers often price gravel by the ton, not the cubic yard. To convert:

1. Calculate cubic yards (as above).
2. Multiply by the density in tons per cubic yard (e.g., 1.4).
3. That gives you tons. Multiply tons by the price per ton to estimate cost.

For example, if you need 2.5 yd³ of crushed stone at 1.4 tons/yd³, that’s 3.5 tons. At $40 per ton, the material cost is $140. Delivery fees are usually separate and often a flat rate or per-mile charge. Many suppliers have a minimum order (often 1–2 tons) and charge extra for partial loads.

If your supplier sells by the cubic yard instead, you can skip the ton conversion and just multiply cubic yards by the price per yard. Always ask which unit they use – it’s a common source of ordering errors.

Common Mistakes and How to Avoid Them

• Mixing units: Entering length in feet and depth in inches without converting. Always convert inches to feet (divide by 12) before multiplying.
• Forgetting compaction: Gravel settles and compacts. If you order exactly the calculated volume, you’ll end up short. Add 10–15% for compacted layers.
• Measuring the top of the area, not the hole: If you’re filling a trench or a recessed area, measure the actual void, not the surrounding ground level.
• Rounding too early: If you round the cubic feet to 17 before dividing by 27, you get 0.63 yd³ instead of 0.62. Keep full precision until the final step.
• Ordering by volume when the supplier sells by weight: Always confirm the pricing unit. A cubic yard of pea gravel weighs less than a cubic yard of wet bank gravel, so the same volume can cost different amounts.

Limits of the Cubic Yard Formula

The formula assumes a perfectly flat, rectangular area with uniform depth. Real projects have slopes, curves, and uneven bases. For a sloped driveway, measure the average depth – not the deepest point. For a curved path, break it into smaller rectangles and add them up. The formula also doesn’t account for gravel lost to wind, spillage, or being pushed aside during spreading. Adding 5–10% extra covers these losses.

Another limit: the density figure (1.4 tons/yd³) is an average. Moisture content can increase weight significantly. If you’re ordering by weight, ask the supplier for the exact density of the material you’re getting, especially for large projects where a 0.1 ton difference per yard adds up.

Frequently Asked Questions

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

It depends on depth. One cubic yard = 27 cubic feet. At 3 inches deep (0.25 ft), it covers 108 square feet (27 ÷ 0.25). At 4 inches deep, it covers 81 square feet. At 6 inches deep, it covers 54 square feet. Divide 27 by the depth in feet to get coverage.

How much gravel do I need for a 10×10 patio?

For a 10×10 area (100 sq ft) at 4 inches deep: 100 × (4/12) = 33.33 cubic feet, divided by 27 = 1.23 cubic yards. Add 10% for compaction → about 1.35 cubic yards. That’s roughly 1.9 tons of crushed stone.

Should I order gravel by the yard or by the ton?

It depends on how your supplier sells it. Many sell by the ton because weight varies by material. If you know the density, you can convert. If you’re unsure, ask the supplier for a quote in both units – they’ll usually give you the total cost either way.

Can I use the calculator for any type of gravel?

Yes, the volume calculation is the same for any loose material – gravel, sand, soil, or mulch. The density (tons per cubic yard) changes, so adjust the weight estimate accordingly. For sand, use about 1.2 tons/yd³; for topsoil, about 1.1 tons/yd³.

How deep should gravel be for a driveway?

For a residential driveway with a compacted base, 4–6 inches of gravel is typical. If you’re laying gravel directly on soil, go with 6 inches. For a parking area that gets heavy vehicles, 8 inches or more may be needed. Always compact in layers – 4 inches at a time – rather than dumping all at once.

What if my area isn’t a rectangle?

Break it into rectangles, triangles, and circles. Calculate each shape’s square footage, add them together, then multiply by depth. For a circle, use π × r². For a triangle, base × height ÷ 2. The calculator works with the total square footage – just enter that as length × width (e.g., if your total area is 200 sq ft, enter length 20 and width 10).

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in length | Length | ft | 10 | 0
in width | Width | ft | 5 | 0
in depth | Depth | in | 4 | 0
out cubic_yards | Cubic Yards | yd³ | (length * width * (depth / 12)) / 27 | 2
out tons | Approx. Tons | tons | ((length * width * (depth / 12)) / 27) * 1.4 | 2