Calculate the volume of any area in cubic yards — for concrete, gravel, soil, mulch or fill. Enter length, width and depth to get cubic yards and cubic metres.
| Item | Value |
|---|
Crushed rock and gravel are essential materials in Australian construction and landscaping. They are sold by weight (tonne) or volume (m³) depending on the supplier.
| Application | Material | Depth |
|---|---|---|
| Concrete slab | Concrete | Order by yd³ |
| Garden soil | Topsoil | Fill depth |
| Driveway gravel | Gravel | 75–100 mm |
| Mulch bed | Mulch | 50–75 mm |
| Backfill | Sand / fill | Varies |
For a slab 10 feet long, 10 feet wide and 4 inches (0.33 ft) thick, multiply 10 × 10 × 0.33 = 33 cubic feet. Divide by 27 (the number of cubic feet in a cubic yard) to get about 1.23 cubic yards, which is roughly 0.94 cubic metres. Rounding up for wastage, you’d order 1.3 cubic yards of concrete.
Australia is metric, so most local suppliers quote in cubic metres — but cubic yards remain common on US-based product specs, imported machinery, online tutorials, and landscaping guides. If you’re following an American how-to or reading a spec sheet in yards, you need to convert to order the right amount here. That’s the main reason this calculator shows both units side by side. One cubic yard is 27 cubic feet, or about 0.765 cubic metres, so a quantity in yards is always a bit smaller than the same number in metres. Keeping both figures visible avoids the common mistake of ordering cubic metres when a guide specified cubic yards, which would leave you about 30% short.
| Gravel Type | Bulk Density | Common Use |
|---|---|---|
| Pea gravel / river pebbles | ~1.5-1.6 t/m³ | Garden beds, decorative |
| Crushed rock (20mm) | ~1.8-1.9 t/m³ | Driveways, drainage |
| Blue metal (20mm) | ~1.9-2.0 t/m³ | Concrete aggregate, driveways |
| Decomposed granite | ~1.6-1.8 t/m³ | Paths, driveways |
| Road base (compacted) | ~2.0-2.2 t/m³ | Sub-base for driveways |
| Application | Recommended Depth |
|---|---|
| Decorative garden bed | 40-50 mm |
| Landscaping path | 50-75 mm |
| Residential driveway | 75-100 mm over compacted base |
| Drainage layer | 100-150 mm |
How do I calculate cubic yards?
Multiply length × width × depth (all in feet) and divide by 27, since one cubic yard is 27 cubic feet. For example, 9 ft × 9 ft × 3 ft = 243 ÷ 27 = 9 cubic yards. This calculator does the conversion and also shows cubic metres.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in one cubic yard (3 ft × 3 ft × 3 ft). So to convert cubic feet to cubic yards, divide by 27. The calculator handles this automatically when you enter your measurements.
How do I convert cubic yards to cubic metres?
One cubic yard equals about 0.765 cubic metres. Since Australia uses metric, this calculator shows both — enter your dimensions and it gives cubic yards and cubic metres side by side.
How many cubic yards of concrete do I need for a slab?
Multiply the slab length × width × thickness in feet, then divide by 27. A 10 ft × 10 ft slab at 4 inches (0.33 ft) is about 1.23 cubic yards. Enter your slab size above to get the exact amount.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in a cubic yard, because a cubic yard is 3 ft × 3 ft × 3 ft. To convert cubic feet to cubic yards, divide by 27.
How do I convert cubic yards to cubic metres?
Multiply cubic yards by 0.765. So 5 cubic yards is about 3.82 cubic metres. This calculator shows both automatically.
What materials is this calculator for?
Any bulk material measured by volume — concrete, topsoil, gravel, mulch, sand or fill. Select the material for a weight estimate as well as the volume.
How much extra should I order?
Add around 10% to allow for wastage, spillage and uneven ground. It’s cheaper to have a small surplus than to run short and pay for a second delivery.