FitAndFillConcrete, gravel, soil and mulch are sold by the cubic yard, but we measure yards in feet and depths in inches. That mismatch is where most ordering mistakes come from. This guide shows what a cubic yard really is, how to get it from three measurements, and how much ground it covers at each depth.
What a cubic yard is
A cubic yard is a cube that is 3 feet long, 3 feet wide and 3 feet tall. Since 3 × 3 × 3 = 27, one cubic yard is 27 cubic feet. Every conversion below comes from that one fact.
From measurements to cubic yards
Measure the length and width in feet and the depth in inches, then:
cubic yards = length (ft) × width (ft) × depth (in ÷ 12) ÷ 27 Dividing the depth by 12 is the step people skip. A 10 × 12 ft patio at 4 in deep is 10 × 12 × (4 ÷ 12) = 40 cubic feet, and 40 ÷ 27 = 1.48 cubic yards. Add an allowance for settling and waste before you order, for example 10 %: 1.63 cubic yards.
How much ground one cubic yard covers
A handy shortcut: because a cubic yard is 27 × 12 = 324 "square-foot-inches", one cubic yard covers 324 ÷ depth (in) square feet.
| Depth | Area covered by 1 cubic yard |
|---|---|
| 1 in | 324 sq ft |
| 2 in | 162 sq ft |
| 3 in | 108 sq ft |
| 4 in | 81 sq ft |
| 6 in | 54 sq ft |
| 8 in | 40.5 sq ft |
| 12 in | 27 sq ft |
How many bags is a cubic yard?
Divide 27 by the volume of one bag and round up. For concrete mix, the yields below come from the QUIKRETE No. 1101 data sheet; other products yield differently, so use the figure printed on your bag.
| Concrete bag | Yield per bag | Bags per cubic yard |
|---|---|---|
| 40 lb | 0.3 cu ft | 90 |
| 50 lb | 0.375 cu ft | 72 |
| 60 lb | 0.45 cu ft | 60 |
| 80 lb | 0.6 cu ft | 45 |
| 90 lb | 0.675 cu ft | 40 |
The 10 × 12 ft patio at 4 in needs 40 cubic feet, which is 40 ÷ 0.6 = 67 bags of 80 lb, before any extra.
Mulch and soil bags are printed with their volume in cubic feet:
| Bag size | Bags per cubic yard |
|---|---|
| 1 cu ft | 27 → 27 |
| 1.5 cu ft | 18 → 18 |
| 2 cu ft | 13.5 → 14 |
| 3 cu ft | 9 → 9 |
Cubic yards and tons
Gravel and stone are often sold by weight. Tons per cubic yard depends on the material, its moisture and the supplier. These figures are one supplier's catalog values (WeGravel) in U.S. short tons of 2,000 lb; ask your own supplier for theirs.
| Material | Tons per cubic yard |
|---|---|
| Crushed stone #57 or #67 | 1.35 |
| Pea gravel | 1.35 |
| Road base (stone with fines) | 1.55 |
| Topsoil | 1.1 |
For example, 4 cubic yards of road base at 1.55 tons per cubic yard is about 6.2 tons.
Common mistakes
- Forgetting to convert inches to feet. A depth of 4 in is 4 ÷ 12 = 0.333 ft in the formula.
- Mixing up cubic yards and square yards. Square yards measure area (9 sq ft each); cubic yards measure volume (27 cu ft each).
- Ordering the exact amount. Ground settles, edges are uneven and some material is lost. Add an allowance.
- Using one bag yield for every brand. Read the volume on your bag.
Frequently asked questions
How many cubic feet are in a cubic yard?
27. It is 3 ft × 3 ft × 3 ft.
How do I get cubic yards for a round area?
Find the area first (π × radius²), then multiply by the depth in feet and divide by 27. The Mulch Calculator handles round beds.
Is a "yard" of material the same as a cubic yard?
In ordering, yes: when a supplier says "a yard of mulch" they mean one cubic yard. If you are not sure, ask.