Metric Unit Calculator
The formula, your substituted values, and the evaluated result are shown below.
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View offerAffiliate link — we may earn a commission at no extra cost to you.Convert square feet and material depth to cubic yards.
This is a planning estimate. Confirm dimensions, allowances, material specifications, applicable codes, and supplier requirements before purchasing or construction.
Convert square feet and material depth to cubic yards.
Concrete, mulch, topsoil and gravel are sold by the cubic yard in the US, but projects are usually measured as an area in square feet and a depth in inches. This calculator joins the two:
Cubic yards = area (ft²) × depth (in) ÷ 324
There are 12 inches in a foot, so depth in inches ÷ 12 gives feet. That makes area × depth a volume in cubic feet. A cubic yard is 3 × 3 × 3 = 27 cubic feet. So you divide by 12 and then by 27, and 12 × 27 = 324.
Ready-mix is often ordered in quarter or half-yard steps, so for this slab I'd order 5.5 yd³. In metric, 4.94 yd³ is 4.94 × 0.7646 = 3.78 m³.
| Depth | ft² covered by 1 yd³ | Typical use |
|---|---|---|
| 2 in | 162 ft² | Mulch or decorative stone top-up |
| 3 in | 108 ft² | New mulch beds, gravel paths |
| 4 in | 81 ft² | Patios, sidewalks, shed slabs |
| 6 in | 54 ft² | Driveways, heavier-duty slabs |
The same maths works for mulch, soil and gravel. Mulch and topsoil are sold by volume, so the answer is your order quantity (plus a little extra for settling). Gravel is often sold by the ton. As a rough guide, one cubic yard of gravel weighs about 1.3–1.5 US tons, but ask your supplier for their figure. If you work in metric, our gravel calculator gives the weight directly.
81 ft² at 4 inches thick, or 54 ft² at 6 inches.
One cubic metre is about 1.308 cubic yards, and one cubic yard is about 0.7646 cubic metres.
Roughly 45 bags of 80 lb premix or 60 bags of 60 lb premix, depending on the product's stated yield. Beyond one or two yards, ready-mix is usually cheaper and easier.