Cubic Yard Calculator Soil: Volume & Weight

A cubic yard calculator for soil works out the volume of soil you need in cubic yards from the length, width, and depth of the area you plan to fill. You enter those three measurements in feet or inches, and the calculator returns the cubic yards, plus an estimated weight in tons based on typical soil density. This is the first number you need before ordering topsoil, garden mix, or fill dirt, because suppliers sell bulk soil by the cubic yard.

Formula

The volume formula is straightforward: multiply length × width × depth to get cubic feet, then divide by 27 to convert to cubic yards (since 1 cubic yard = 27 cubic feet). In symbols:

V (yd³) = (L × W × D) / 27

• L = length of the area, in feet
• W = width of the area, in feet
• D = depth of the soil layer, in feet (convert inches to feet by dividing by 12)
• V = volume of soil, in cubic yards

The weight estimate uses a typical bulk density for moist topsoil of about 1.1 tons per cubic yard (roughly 2,200 lb/yd³). That density varies widely—from about 0.8 tons/yd³ for dry loose fill to over 1.3 tons/yd³ for wet clay—so the tonnage is an approximation, not a precise delivery weight.

Worked Example

Using the calculator defaults: a bed 10 ft long, 5 ft wide, and 6 inches deep.

1. Convert depth to feet: 6 in ÷ 12 = 0.5 ft.
2. Compute cubic feet: 10 × 5 × 0.5 = 25 ft³.
3. Convert to cubic yards: 25 ÷ 27 = 0.926 yd³.
4. Estimate weight: 0.926 × 1.1 = 1.02 tons.

The calculator rounds to 0.93 cubic yards and 1.02 tons. That matches the block output exactly.

Why Soil Is Sold in Cubic Yards

Bulk soil, mulch, gravel, and compost are almost always sold by the cubic yard rather than by weight or by bag. The reason is practical: a cubic yard is a fixed volume (3 ft × 3 ft × 3 ft), so it is easy for the supplier to measure with a bucket or loader. Weight varies with moisture, compaction, and soil type, so pricing by volume avoids arguments about how much a wet load weighs. Bags, by contrast, are sold by cubic foot (usually 0.75–1.5 ft³ per bag), which is why you often see the conversion factor 27 ft³ = 1 yd³.

For a small project, buying bags may make sense—you can carry them yourself and avoid a delivery fee. But for anything over about 10–15 bags, bulk delivery is usually cheaper per cubic foot. A single cubic yard of soil weighs roughly 1 ton, so a standard pickup truck can carry only about half a yard safely; check your vehicle’s payload rating before loading.

How to Measure Your Area Correctly

The most common mistake is mixing units. Always measure length and width in the same unit (feet), and depth in inches or feet, then convert consistently. For a rectangular bed, the formula is simple. For irregular shapes, break the area into rectangles, compute each one, and add the volumes together. For circular beds, use the formula for a cylinder: π × radius² × depth, then divide by 27.

Depth is the trickiest measurement. For new garden beds, 6 inches is a common minimum for planting. For raised beds, you often need 12–18 inches. For filling a low spot in a lawn, 2–3 inches may be enough. Always measure the actual depth you want after settling—soil compacts over time, so many gardeners order 10–20% extra to account for settling.

Common Mistakes When Ordering Soil

• Mixing feet and inches without converting—this can double or halve your volume.
• Forgetting the 27 conversion—ordering cubic feet when you meant cubic yards gives you 1/27 of what you need.
• Ignoring compaction—fresh soil settles, so the volume you order is more than the final settled depth.
• Assuming 1 yard = 1 ton—weight varies; always ask the supplier for the density of the specific soil they deliver.
• Measuring the top of the bed instead of the actual fill depth—if the bed has sloped sides, the volume is less than a simple box formula.

Another common misconception is that a cubic yard of soil covers 100 square feet at 3 inches deep. That is true (100 ft² × 0.25 ft = 25 ft³, which is just under 1 yd³), but it only works at exactly 3 inches. At 6 inches, it covers 50 ft²; at 12 inches, only 25 ft².

How to Read the Result

The cubic yard number is what you quote to the supplier. If the calculator says 0.93 yd³, you would order 1 yard (suppliers rarely deliver fractions below half a yard, and many have a minimum order of 1–2 yards). The weight estimate tells you how much the soil will weigh when wet, which matters for transport and for structural loads (e.g., a rooftop garden). For a 10×5×6-inch bed, 1.02 tons is a realistic wet weight; dry topsoil would be closer to 0.8 tons.

If your project is large (more than a few yards), the supplier will likely ask whether you want the soil screened (to remove rocks and clods) or unscreened. Screened soil is more uniform but costs more per yard. The volume calculation is the same either way.

Limits of the Calculator

This calculator assumes a flat, rectangular area with vertical sides. It does not account for slopes, irregular shapes, or soil settlement. For a sloped site, you need the average depth, not the deepest point. For a triangular bed, use the triangle area formula (½ × base × height) and multiply by depth. For a raised bed with tapered sides, the volume is less than the top dimensions suggest—use the average of top and bottom dimensions.

The weight estimate is the weakest part. Soil density ranges from about 1,900 lb/yd³ for dry sandy loam to over 2,600 lb/yd³ for wet clay. If you need an exact delivery weight (for trucking limits or structural calculations), ask the supplier for the specific density of the material they sell. The calculator’s 1.1 tons/yd³ is a safe middle value for moist garden soil.

Frequently Asked Questions

How many bags of soil equal a cubic yard?

A cubic yard is 27 cubic feet. If you buy 1-cubic-foot bags, you need 27 bags. Most retail bags are 1.5 cubic feet (18 bags per yard) or 2 cubic feet (13.5 bags per yard). Check the bag label—it always lists cubic feet, not weight, so the conversion is straightforward.

How deep should soil be for a raised garden bed?

For most vegetables and flowers, 12 inches is the recommended minimum. Some shallow-rooted plants (lettuce, herbs) can grow in 6–8 inches, but deep-rooted crops like tomatoes and carrots need 12–18 inches. The calculator uses the depth you enter, so measure the actual inside height of your bed frame.

Why does my soil order seem too small?

Soil compacts significantly after watering and settling. A yard of loose soil may settle to 0.8–0.9 yards of settled soil. For a new bed, order 10–20% extra to account for this. Also, double-check that you converted depth to feet—many people enter 6 (inches) as if it were feet, which gives 12 times too much soil.

Can I use this calculator for mulch or gravel?

Yes, the volume calculation is identical for any bulk material. The weight estimate, however, is only for soil. Mulch weighs about 0.4–0.6 tons per cubic yard, while gravel weighs 1.3–1.5 tons per cubic yard. Use the cubic yard number for ordering, but ignore the weight output for non-soil materials.

What is the difference between topsoil, fill dirt, and garden soil?

Topsoil is the natural upper layer of soil, rich in organic matter, good for lawns and planting. Fill dirt is subsoil, lower in organic matter, used for leveling or filling holes. Garden soil is a manufactured blend of topsoil, compost, and other amendments, designed for raised beds. The volume calculation is the same for all, but the weight and price per yard differ.

How do I measure an irregularly shaped area?

Divide the area into rectangles, triangles, or circles, calculate each volume separately, and add them together. For a curved border, approximate with a series of rectangles—the error is usually small. For a circle, use π × radius² × depth. For a triangle, use ½ × base × height × depth. Each sub-volume is then converted to cubic yards by dividing by 27.

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in len | Length | ft | 10 | 0
in wid | Width | ft | 5 | 0
in dep | Depth | in | 6 | 0
out yards | Cubic yards | yd³ | (len * wid * (dep / 12)) / 27 | 2
out tons | Estimated weight | tons | yards * 1.1 | 2