Cubic Yards Calculator: Formula & How to Use

This calculator works out the volume of a rectangular space in cubic yards when you enter its length, width, and depth (or height). You get the result in cubic yards, plus the equivalent in cubic feet and cubic meters, so you can order soil, mulch, concrete, or gravel with confidence. Just enter your measurements in feet, inches, yards, or meters, and the tool handles the conversions.

Formula

The basic formula for volume in cubic yards is:

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

Because 1 yard = 3 feet, 1 cubic yard = 3 × 3 × 3 = 27 cubic feet. If your depth is in inches (common for mulch or gravel), first convert it to feet by dividing by 12. The variables are:

• Length – the longest horizontal dimension, in feet (or converted to feet).
• Width – the horizontal dimension perpendicular to length, in feet.
• Depth – how deep the material goes, in feet (inches ÷ 12).
• 27 – the number of cubic feet in one cubic yard.

For a circular area (like a tree ring or sandbox), use: Volume = π × radius² × depth, then divide by 27 to get cubic yards. For a triangular area, use 0.5 × base × height × depth ÷ 27.

Worked Example

Let’s use the default values from the calculator: a bed that is 10 ft long, 5 ft wide, and 4 inches deep.

1. Convert depth to feet: 4 in ÷ 12 = 0.3333 ft.
2. Find volume in cubic feet: 10 × 5 × 0.3333 = 16.665 ft³.
3. Convert to cubic yards: 16.665 ÷ 27 = 0.6172 yd³.
4. Rounded to two decimals: 0.62 cubic yards.

The calculator shows the same 0.62 yd³, along with 16.67 ft³ and 0.47 m³. That’s the amount of material you’d need to fill the space level to the top.

When to Use a Cubic Yards Calculator

You’ll reach for this calculator whenever you need to order bulk materials or plan a project involving volume:

• Landscaping: topsoil, garden soil, compost, mulch, or sand for a raised bed or lawn.
• Construction: concrete for a slab, footings, or posts; gravel or crushed stone for a driveway or base.
• Removal: estimating how much dirt or debris you need to haul away.
• Filling: a pond, pool, or trench with a uniform depth.

Because materials are sold by the cubic yard (or fraction thereof), knowing your volume before you call the supplier prevents both overordering (wasted money) and underordering (a second delivery fee).

How to Read the Result

The result is the exact volume of a rectangular prism with your measurements. But in practice, you rarely fill a space perfectly flat to the top. For mulch, you might want a 3-inch layer, not the 4-inch default. For gravel, you often need a compacted depth, which means you might order 10–15% extra to account for settling. For concrete, you usually order slightly more than the calculated volume to avoid running short on a pour.

If your project has an irregular shape, divide it into rectangles, calculate each one, and add the cubic yards together. For a slope, measure the average depth rather than the deepest point.

Common Mistakes and How to Avoid Them

Here are the most frequent errors people make when calculating cubic yards:

• Mixing units: Entering length in feet and depth in inches without converting. Always use the same unit (feet) for all three dimensions.
• Forgetting the ÷27: Some people compute cubic feet and stop. Cubic yards is a different unit – you must divide by 27.
• Using the wrong formula for circles: For a circle, the area is π × r², not π × diameter. Double-check you’re using the radius.
• Rounding too early: If you round 0.3333 ft to 0.3 ft, your final answer will be off by about 10%. Keep full precision until the end.
• Ignoring waste: For loose materials, add 5–10% for spillage and compaction. For concrete, add 5–10% as a safety margin.

Limits of the Formula

This calculator assumes a perfect rectangular shape with vertical sides and a flat bottom. Real-world spaces often have sloped sides, uneven ground, or rounded corners. For those, the formula gives an approximation – usually good enough for ordering materials, but not for precise engineering. Also, the formula gives the volume of the space, not the weight of the material. A cubic yard of mulch weighs about 400–800 lb, while a cubic yard of gravel weighs about 2,400–2,900 lb, and a cubic yard of concrete weighs about 4,000 lb. Check with your supplier for the specific weight, especially if you’re concerned about load limits.

Alternatives to a Cubic Yards Calculator

If you don’t have a calculator handy, you can do the math manually using the formula above. Or, you can use a simpler rule of thumb: for a 10 ft × 10 ft area, 1 inch deep is about 0.31 cubic yards (10 × 10 × 1/12 ÷ 27 = 0.31). Multiply that by your depth in inches to get a quick estimate. For example, 3 inches deep over 10×10 ft is about 0.93 yd³. This works for any square or rectangle, but the exact calculator is more reliable for odd dimensions.

Another alternative is to ask your supplier: many landscaping and construction companies have their own volume calculators or will help you figure out the order size. Just be ready with your length, width, and desired depth in feet.

Frequently Asked Questions

How many cubic feet are in a cubic yard?

There are 27 cubic feet in one cubic yard. This comes from 1 yard = 3 feet, so 1 yd³ = 3 ft × 3 ft × 3 ft = 27 ft³. To convert cubic feet to cubic yards, divide by 27.

How do I calculate cubic yards from inches?

First convert all measurements to feet. If your depth is in inches, divide by 12 to get feet. Then multiply length (ft) × width (ft) × depth (ft) and divide by 27. For example, a 12 ft × 6 ft area with 6 inches of mulch: 12 × 6 × (6/12) = 36 ft³, then 36 ÷ 27 = 1.33 yd³.

What is the difference between a cubic yard and a yard?

A yard is a unit of length (3 feet). A cubic yard is a unit of volume (3 feet × 3 feet × 3 feet). You can’t convert directly between them – you need three dimensions to get volume. A square yard is area (3 ft × 3 ft = 9 ft²), which also isn’t the same as a cubic yard.

How much does a cubic yard of soil weigh?

It varies by material and moisture. Dry topsoil typically weighs about 1,800–2,200 lb per cubic yard, while wet soil can weigh more. Mulch is much lighter at 400–800 lb per cubic yard. Gravel and sand are heavier, around 2,500–3,000 lb per cubic yard. Always confirm with your supplier, as weight affects delivery costs and vehicle limits.

Can I use this calculator for concrete?

Yes, the volume calculation is the same. However, concrete is usually ordered in cubic yards, and you should add 5–10% for waste and spillage. For a slab, measure the length, width, and thickness (in feet) and use the same formula. Note that concrete is often sold in fractions of a cubic yard, so round up to the nearest quarter yard.

How do I measure a sloped area?

For a sloped surface, measure the depth at several points and take the average. Use that average in the formula. For a very irregular slope, you might need to break the area into smaller rectangles and calculate each separately, then add the volumes together.

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in l | Length | ft | 10 | 0
in w | Width | ft | 5 | 0
in d | Depth | in | 4 | 0
out cubic_yards | Cubic yards | yd³ | (l * w * (d / 12)) / 27 | 2
out cubic_feet | Cubic feet | ft³ | l * w * (d / 12) | 2
out cubic_meters | Cubic meters | m³ | (l * w * (d / 12)) * 0.0283168 | 2