Rectangle / Slab
yd3 = (Length ft x Width ft x Thickness in / 12) / 27
Concrete volume · Updated 2026
Cubic Yards Calculator: Concrete Volume, Bags & Cost for Any Shape
Enter dimensions below to get cubic yards, cubic feet, number of bags, and estimated concrete cost. Supports slabs, columns, footings, steps, and custom volumes.
Cubic Yards - Key Conversions
1 cubic yard = 27 cubic feet
1 cubic yard = 46,656 cubic inches
1 cubic yard = 0.7646 cubic meters
1 cubic yard = 764.6 liters
Concrete coverage per 1 yd3: 4" thick covers 81 sq ft; 6" thick covers 54 sq ft. One yard equals 45 bags of 80 lb mix.
Shape
Cubic Yard Calculator by Shape
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Results
Rectangle · Concrete
Includes 10% waste
yd3
5.43
raw 4.94
ft3
146.67
raw 133.33
Bags
245
80 lb bags
Cost
$977
$180/yd3
Also: 4.15 m3 · 4,153.14 L.
Concrete bags: 245 x 80 lb · 326 x 60 lb · 392 x 50 lb · 489 x 40 lb. Selected bags cost about $1,838.
Coverage check: at 4" thick, 1 yd3 covers 81 sq ft. Your area 400 / coverage = 4.94 yd3 raw.
Above 4 yd3 minimum or non-concrete material - no short-load warning.
Cubic Yards Coverage Chart - Concrete, Gravel & More
How much area does 1 cubic yard cover at various depths?
| Thickness | Coverage per 1 yd3 | Common Application |
|---|---|---|
| 2 in | 162 sq ft | Thin overlay, topping slab |
| 3 in | 108 sq ft | Lightweight patio, walkway |
| 4 in | 81 sq ft | Standard patio, driveway, shed base |
| 5 in | 65 sq ft | Heavy-duty driveway, garage |
| 6 in | 54 sq ft | Foundation slab, RV pad |
| 8 in | 40 sq ft | Structural wall, heavy foundation |
| 12 in | 27 sq ft | Thick wall, deep footing |
| Area | 3 in thick | 4 in thick | 5 in thick | 6 in thick |
|---|---|---|---|---|
| 100 sq ft | 0.93 yd3 | 1.23 yd3 | 1.54 yd3 | 1.85 yd3 |
| 200 sq ft | 1.85 yd3 | 2.47 yd3 | 3.09 yd3 | 3.70 yd3 |
| 300 sq ft | 2.78 yd3 | 3.70 yd3 | 4.63 yd3 | 5.56 yd3 |
| 400 sq ft | 3.70 yd3 | 4.94 yd3 | 6.17 yd3 | 7.41 yd3 |
| 500 sq ft | 4.63 yd3 | 6.17 yd3 | 7.72 yd3 | 9.26 yd3 |
| 600 sq ft | 5.56 yd3 | 7.41 yd3 | 9.26 yd3 | 11.11 yd3 |
| 800 sq ft | 7.41 yd3 | 9.88 yd3 | 12.35 yd3 | 14.81 yd3 |
| 1,000 sq ft | 9.26 yd3 | 12.35 yd3 | 15.43 yd3 | 18.52 yd3 |
| Material | 2 in depth | 3 in depth | 4 in depth | Notes |
|---|---|---|---|---|
| Gravel / Crushed Stone | 162 sq ft | 108 sq ft | 81 sq ft | Driveway base, drainage |
| Sand | 162 sq ft | 108 sq ft | 81 sq ft | Paver base, sandbox |
| Topsoil / Fill | 162 sq ft | 108 sq ft | 81 sq ft | Garden beds |
| Mulch | 162 sq ft | 108 sq ft | 81 sq ft | Landscape beds |
| Concrete (4 in slab) | - | - | 81 sq ft | Standard residential |
How to Calculate Cubic Yards - Step-by-Step
The core math is simple: measure in feet, calculate cubic feet, then divide by 27.
Cubic Yards Formula
Step 1: convert depth to feet. Step 2: Volume ft3 = length x width x depth. Step 3: Volume yd3 = ft3 / 27. Step 4: add waste. Example: 20 x 20 x 4 in = 133.3 ft3 = 4.94 yd3 raw; +10% = 5.43 yd3.
Round Slab / Cylinder
yd3 = (3.14159 x radius ft2 x thickness ft) / 27
Strip Footing
yd3 = (Length ft x Width in / 12 x Depth in / 12) / 27
Round Column / Post
yd3 = (3.14159 x (Diameter in / 24)^2 x Height ft x Quantity) / 27
For steps, walls, tubes, and irregular shapes, use the concrete calculator for all shapes.
Cubic Yards of Concrete - Common Projects Quick Reference
Includes 10% waste factor. Ready-mix at $179.89/yd3.
| Project | Dimensions | Thickness | Cubic Yards | 80 lb Bags | Ready-Mix Cost |
|---|---|---|---|---|---|
| Small patio | 10x10 ft | 4 in | 1.36 yd3 | 62 bags | $245 + short load |
| Standard patio | 20x20 ft | 4 in | 5.43 yd3 | 245 bags | $977 |
| 1-car driveway | 12x20 ft | 4 in | 2.96 yd3 | 133 bags | $532 + short load |
| 2-car driveway | 16x40 ft | 4 in | 10.83 yd3 | 487 bags | $1,947 |
| 1-car garage | 12x20 ft | 4 in | 2.96 yd3 | 133 bags | $532 + short load |
| 2-car garage | 24x24 ft | 4 in | 7.83 yd3 | 352 bags | $1,407 |
| Shed base | 12x16 ft | 4 in | 2.61 yd3 | 118 bags | $469 + short load |
| Sidewalk | 4x20 ft | 4 in | 0.99 yd3 | 45 bags | $178 + short load |
| Strip footing | 40 lin ft | 12x8 in | 0.99 yd3 | 45 bags | $178 + short load |
| Deck posts (4) | 10 in dia x 4 ft | - | 0.36 yd3 | 16 bags | $65 + short load |
| Sonotube 12 in x 4 ft (4 posts) | - | - | 0.52 yd3 | 24 bags | $94 + short load |
| Concrete steps (3) | 4 ft wide | 7/11 in | 0.53 yd3 | 24 bags | $95 + short load |
After you know volume, compare ready-mix concrete prices, estimate how many bags of concrete, open the concrete slab calculator, or use the concrete driveway calculator.
Cubic Yards Conversion Table - All Units
| Cubic Yards | Cubic Feet | Cubic Inches | Cubic Meters | Liters | US Gallons |
|---|---|---|---|---|---|
| 0.1 yd3 | 2.70 ft3 | 4,666 in3 | 0.0765 m3 | 76.5 L | 20.2 gal |
| 0.25 yd3 | 6.75 ft3 | 11,664 in3 | 0.1911 m3 | 191.1 L | 50.5 gal |
| 0.5 yd3 | 13.5 ft3 | 23,328 in3 | 0.3823 m3 | 382.3 L | 101.0 gal |
| 1 yd3 | 27 ft3 | 46,656 in3 | 0.7646 m3 | 764.6 L | 201.97 gal |
| 2 yd3 | 54 ft3 | 93,312 in3 | 1.529 m3 | 1,529 L | 404 gal |
| 3 yd3 | 81 ft3 | 139,968 in3 | 2.294 m3 | 2,294 L | 606 gal |
| 5 yd3 | 135 ft3 | 233,280 in3 | 3.823 m3 | 3,823 L | 1,010 gal |
| 10 yd3 | 270 ft3 | 466,560 in3 | 7.646 m3 | 7,646 L | 2,020 gal |
| 20 yd3 | 540 ft3 | 933,120 in3 | 15.29 m3 | 15,291 L | 4,039 gal |
| Cubic Feet | Cubic Yards | Notes |
|---|---|---|
| 1 ft3 | 0.037 yd3 | - |
| 10 ft3 | 0.370 yd3 | Small patch |
| 27 ft3 | 1.000 yd3 | Exactly 1 cubic yard |
| 50 ft3 | 1.852 yd3 | - |
| 100 ft3 | 3.704 yd3 | - |
| 135 ft3 | 5.000 yd3 | - |
| 270 ft3 | 10.000 yd3 | Full truckload |
For installed pricing, see concrete slab cost.
Cubic Yards Calculator - Frequently Asked Questions
How do I calculate cubic yards of concrete?+
Multiply length x width x (thickness / 12) in feet to get cubic feet, then divide by 27 to get cubic yards. Add 10% for waste. A 20x20 ft patio at 4 inches is 4.94 yd3 raw, or 5.43 yd3 with waste.
How many cubic feet are in a cubic yard?+
There are exactly 27 cubic feet in one cubic yard. Divide cubic feet by 27 to get cubic yards, or multiply cubic yards by 27 to get cubic feet.
How many cubic yards do I need?+
It depends on area and depth. One cubic yard covers 81 sq ft at 4 inches thick or 54 sq ft at 6 inches thick. A 640 sq ft driveway at 4 inches needs about 10.8 yd3 with waste.
How many cubic yards of concrete are in a truck?+
A standard ready-mix truck holds about 8-10 cubic yards. Orders under 4 cubic yards often get a short-load fee.
How do I convert square feet to cubic yards?+
Use yd3 = (square feet x depth in inches) / 324. For example, 400 sq ft at 4 inches deep is 4.94 yd3.
How much does a cubic yard of concrete weigh?+
One cubic yard of standard concrete weighs about 4,050 lb, or 2.025 tons. Gravel is about 2,800 lb per yd3, topsoil about 2,200 lb, and mulch about 400-800 lb.
What is the difference between cubic yards and square yards?+
Cubic yards measure volume: length x width x depth. Square yards measure area only. Concrete, gravel, soil, and mulch are usually ordered by cubic yard.
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