Calculate fill volume for landscaping, concrete, and bulk material projects. Enter surface dimensions and depth to get cubic yards, cubic feet, metric volume, and optional material weight estimates.
Measure the longest side of the area to fill
Use average width if the space is irregular
Typical: 2–3 in mulch, 4 in gravel, 4 in concrete slabs
All dimensions converted to yards internally
Weight estimates help plan truck loads and delivery fees
Volume = Length × Width × Depth (all converted to yards). 1 cubic yard = a cube 3 ft × 3 ft × 3 ft.
30 × 20 ft, 4 in deep → 7.41 yd³
15 × 10 ft, 6 in deep → 2.78 yd³
20 × 20 ft, 4 in deep → 4.94 yd³
12 × 8 ft, 3 in deep → 0.89 yd³
| Unit | = 1 Cubic Yard | Common Use |
|---|---|---|
| Cubic Feet | 27 ft³ | General building volume |
| Cubic Inches | 46,656 in³ | Small-product estimation |
| Cubic Meters | 0.7646 m³ | Metric project planning |
| US Gallons | 201.97 gal | Liquid volume equivalent |
| Liters | 764.55 L | International liquid equivalent |
| Material | Density (tons/yd³) | Weight (lb/yd³) | Notes |
|---|---|---|---|
| Crushed Gravel | 1.5 | 3,000 | Average 3/4 in crushed stone weighs about 1.45–1.55 tons per cubic yard. |
| Dry Sand | 1.35 | 2,700 | Dry mason or play sand typically ranges from 1.30–1.40 tons per cubic yard. |
| Screened Topsoil | 1 | 2,000 | Moist topsoil averages close to 2,000 lb (1 ton) per cubic yard. |
| Wood Mulch | 0.4 | 800 | Shredded hardwood mulch is light—roughly 800 lb per cubic yard. |
| Ready-Mix Concrete | 2 | 4,000 | Hardened concrete weighs about 4,000 lb (2 tons) per cubic yard. |
A cubic yard is the volume of a cube measuring exactly 3 feet on each side — 3 ft × 3 ft × 3 ft = 27 cubic feet. It is the standard unit for bulk materials in North American construction, landscaping, and agriculture. When you order mulch, gravel, topsoil, or ready-mix concrete, suppliers quote prices per cubic yard.
Understanding cubic yards lets you compare quotes from different suppliers, avoid under- or over-ordering, and plan truck loads accurately. The formula is simple: Volume (yd³) = Length × Width × Depth, with all dimensions converted to yards first.
Example: A driveway 30 ft × 20 ft with 4-inch (0.33 ft) gravel base: Convert to yards: 30/3 = 10 yd, 20/3 = 6.67 yd, 4/36 = 0.111 yd. Volume = 10 × 6.67 × 0.111 ≈ 7.41 yd³. At 1.5 tons/yd³ for gravel: 11.1 tons of material.
First time I ordered concrete, the dispatcher on the phone asked how many yards I needed. I had measured my patio in feet. I said something embarrassing. She paused, then walked me through it like she'd done a hundred times that week — because she had.
Here's the trap that catches almost everyone: a "yard" of concrete, gravel, mulch, or topsoil isn't a length. It's a cubic yard — a cube three feet on every side. And the jump from the feet you measured to the cubic yards you order is bigger than your brain wants it to be. People miss it constantly and end up either short a load or staring at a leftover mound of dirt they paid for.
Let's take apart what's really happening when you "order a few yards," because the math has one counterintuitive move in it that costs people real money.
A cubic yard is the volume of a 3 ft × 3 ft × 3 ft cube. That equals 27 cubic feet — not 9, and definitely not 3. This single conversion factor is where most ordering mistakes start.
Ask someone how many cubic feet are in a cubic yard and a lot of people guess 3. It feels right. A yard is 3 feet, after all. But you're not converting a line — you're converting a box, and a box has three dimensions all multiplying at once.
Three feet long, three feet wide, three feet tall:
Translation: stacking changes everything. Each dimension triples, and tripling three times means multiplying by 27. That's why a pile of "one yard" of mulch is shockingly large when it lands on your driveway — it's the size of a small refrigerator laid on its side.
So the whole job comes down to one chain: measure your space in feet, multiply to get cubic feet, then divide by 27.
This is where the second mistake hides. Length and width you measure in feet without thinking. But depth — the thickness of your slab or the layer of gravel — is almost always in inches. Drop inches straight into the formula and your number comes out 12 times too big.
Say you're pouring a patio: 20 feet long, 12 feet wide, 4 inches thick. First, turn 4 inches into feet:
Now run the full calculation:
So you'd order 3 cubic yards. Forget the inch-to-foot step and the formula spits out 35.5 yards — a full concrete truck and then some, for a backyard patio. That's not a rounding error. That's a five-figure phone call.
The calculator gives you the exact volume of a perfect rectangle with a perfectly level base. Your yard is not that. The ground dips. The forms bow out a little. Some concrete sticks to the chute and the wheelbarrow. Mulch settles and compresses.
The trade rule of thumb: add 5–10% for waste and over-excavation. For concrete specifically, the National Ready Mixed Concrete Association notes that uneven subgrade is the most common reason a pour comes up short. Running out mid-pour means a cold joint — a weak seam where fresh concrete meets concrete that's already starting to set.
| Project (L × W × Depth) | Exact yd³ | Order w/ 10% |
|---|---|---|
| Patio — 20 × 12 × 4 in | 2.96 | 3.25 |
| Driveway — 40 × 16 × 5 in | 9.88 | 10.9 |
| Mulch bed — 30 × 10 × 3 in | 2.78 | 3.1 |
| Garage slab — 24 × 24 × 6 in | 10.67 | 11.7 |
Exact volume uses depth converted to feet, divided by 27. "Order" column adds a 10% allowance for waste, spillage, and uneven base.
One more thing that trips people up at the supply yard: not everything is sold by volume. Concrete and mulch you buy by the cubic yard. But crushed stone and gravel are often sold by weight — tons — even though you measured the hole in cubic yards.
The bridge between them is density. A cubic yard of gravel weighs roughly 1.4 tons, but it varies by stone type and moisture, so the conversion isn't a clean single number. If gravel is your project, the guide to sizing a gravel driveway walks through the tons-vs-yards conversion specifically, so you don't order three yards of stone and get billed for four tons.
Exactly 27. A cubic yard is a cube measuring 3 feet on each side, and 3 × 3 × 3 = 27 cubic feet. To go from cubic feet to cubic yards, divide by 27; to go the other way, multiply by 27.
It depends entirely on depth. One cubic yard spread 3 inches deep covers about 108 square feet; at 4 inches deep it covers about 81 square feet; at 6 inches it covers 54 square feet. Thinner layer, more coverage — the same 27 cubic feet just gets stretched over more ground.
About 45 bags. An 80 lb bag of premixed concrete yields roughly 0.6 cubic feet, and a cubic yard is 27 cubic feet, so 27 ÷ 0.6 ≈ 45 bags. Past roughly one cubic yard, ordering a ready-mix truck is usually cheaper and far less back-breaking than mixing bags by hand.
Calculate volume in cubic feet from length, width, and height with unit conversions to cubic yards, gallons, and liters.
Estimate gravel volume, weight, and cost for driveways, paths, and landscaping projects based on area, depth, and gravel type.
Calculate lumber volume in board feet for woodworking projects. Supports thickness formats like 4/4 and unit toggles.
Calculate riser height, tread depth, stringer length, and total run with IRC building-code compliance checks.