Cubic Yards, Cubic Feet, Bags and Tons: Converting Materials

Volume units

A cubic yard is the unit bulk landscape yards and ready-mix plants use. It sounds small, but it is a lot of material: enough mulch to cover 108 square feet 3 inches deep.

From area and depth to volume

Square feet × depth in inches ÷ 12 = cubic feet. Divide by 27 for cubic yards. Our mulch, soil and gravel calculator does this for you; if your area is not a rectangle, the measuring guide helps.

Bags per cubic yard

Bagged mulch, soil and compost are labeled by volume, usually in cubic feet. Divide 27 by the bag size:

Some bags are labeled in quarts or liters. There are about 25.7 dry quarts in a cubic foot and 28.3 liters.

Concrete: sold by weight, used by volume

Concrete mix is sold by weight but the bag also states its yield in cubic feet. A widely sold standard mix lists 0.30 cubic feet per 40 lb bag, 0.45 per 60 lb and 0.60 per 80 lb. That gives:

Specialty mixes can differ, so read your bag. See the concrete calculator.

Tons: why you need the supplier's number

Converting volume to weight needs a density: pounds per cubic yard. For stone and gravel that number changes with:

• The rock itself. Different rock types have different densities.
• Size and grading. A mix of sizes packs tighter than uniform stones.
• Loose vs compacted. Ohio DOT's specification for one stabilized crushed aggregate uses 3,800 lb per cubic yard compacted in place. The same stone loose in a truck occupies more space per ton.
• Moisture. Wet sand and stone weigh more.

Quarries and yards selling by the ton will tell you the figure they use for each product. Multiply cubic yards by that figure and divide by 2,000 to get tons.

Ordering tips

• Round bulk orders up to the supplier's increment (often a half or whole cubic yard).
• Add 5–10% for settling and compaction on mulch, soil and gravel.
• Ask about delivery minimums and where the truck can drop the load.
• For large concrete jobs, compare bags with ready-mix; see our bags vs ready-mix guide.

Worked example: a garden refresh

You are mulching 320 square feet of beds 3 inches deep and filling a raised bed 8 × 4 feet and 10 inches deep with soil.

• Mulch: 320 × 3 ÷ 12 = 80 cubic feet = 2.96 cubic yards. In 2 cubic foot bags, that is 40 bags. In bulk, order 3 cubic yards, or a little more to allow for settling.
• Soil: 8 × 4 = 32 square feet × 10 ÷ 12 = 26.7 cubic feet = just under 1 cubic yard. In 1.5 cubic foot bags, 18 bags.

At 40 bags, bulk mulch delivery is worth pricing. For the raised bed, one cubic yard of bulk soil or 18 bags are close enough in quantity that convenience and price decide.

Common mistakes

• Forgetting to divide inches by 12. 200 square feet × 3 inches is 50 cubic feet, not 600.
• Dividing by 9 instead of 27. Nine converts square feet to square yards; 27 converts cubic feet to cubic yards.
• Assuming a "yard" of gravel is a fixed weight. Always confirm the supplier's weight per yard if you are buying by the ton.

Common questions

How many cubic feet are in a yard?

27. A cubic yard is a cube 3 feet on each side: 3 × 3 × 3 = 27 cubic feet.

How many tons is a yard of gravel?

It depends on the stone and whether it's loose or compacted. As one example, Ohio DOT uses 3,800 lb (1.9 tons) per cubic yard for a compacted crushed aggregate, while loose stone weighs less per yard. Ask your supplier for the figure for the product you are buying.

How many bags of concrete are in a yard?

45 bags of 80 lb, 60 bags of 60 lb or 90 bags of 40 lb standard mix, based on yields of 0.60, 0.45 and 0.30 cubic feet per bag.

What is a cubic meter in cubic yards?

About 1.31 cubic yards. One cubic yard is about 0.76 cubic meters (NIST).