Square Feet to Cubic Yards Calculator
Turn an area and a depth into cubic yards for mulch, soil, gravel, or concrete orders, with bag counts and a waste allowance built in. Honest rule: square feet alone cannot become cubic yards, because volume needs a depth. This calculator always asks for one, so it works as a mulch calculator, soil calculator, and concrete ordering helper in one.
Forward: area and depth to cubic yards
Enter the area to cover and how deep the material goes.
- Cubic feet
- 33.3333
- Cubic meters
- 0.9439
- With 10% waste
- 1.358 yd³
- Bags needed (exact)
- 16.6667
- Bags to buy (rounded up)
- 17
- Bags to buy with waste
- 19
Example: 100 sq ft at 4 in deep = 100 x (4/12) = 33.3333 ft³; 33.3333 / 27 = 1.2346 yd³.
Reverse: cubic yards and area to depth
You have a volume (for example, a delivered pile) and want to know how deep it spreads.
- Feet
- 0.54
- Centimeters
- 16.4592
Example: 2 yd³ over 100 sq ft = 2 x 27 / 100 x 12 = 6.48 inches.
Quick reference: square feet to cubic yards
Common area and depth combinations, in cubic yards. Mulch is usually 2 to 4 inches; concrete slabs are usually 4 to 6 inches.
| Area | 2 in | 3 in | 4 in | 6 in |
|---|---|---|---|---|
| 100 sq ft | 0.6173 | 0.9259 | 1.2346 | 1.8519 |
| 250 sq ft | 1.5432 | 2.3148 | 3.0864 | 4.6296 |
| 500 sq ft | 3.0864 | 4.6296 | 6.1728 | 9.2593 |
| 1,000 sq ft | 6.1728 | 9.2593 | 12.3457 | 18.5185 |
Worked examples
1. Mulch bed: 100 sq ft at 4 inches
100 x (4/12) = 33.3333 ft³; / 27 = 1.2346 yd³.
In 2 ft³ bags: 17 bags (33.3333 / 2 = 16.6667, rounded up). With 10% waste: 19 bags.
2. Large mulch area: 500 sq ft at 3 inches
500 x (3/12) = 125 ft³ = 4.6296 yd³.
In 3 ft³ bags: 125 / 3 = 41.6667, so buy 42 bags. At this volume, bulk delivery (about 5 yd³ with waste) is usually cheaper than bags.
3. Concrete patio: 200 sq ft at 6 inches
200 x (6/12) = 100 ft³ = 3.7037 yd³.
Order a ready-mix truck: 3.7037 yd³ plus 5-10% waste is about 3.9 to 4.1 yd³. This is above typical short-load minimums, so no short-load fee in most areas (confirm with your supplier).
4. Reverse: how deep is 2 yd³ over 100 sq ft?
2 x 27 / 100 x 12 = 6.48 inches deep.
Useful when a pile is delivered and you want to check the spread depth before ordering more.
Bags or a truck? A quick rule
Frequently asked questions
How do you convert square feet to cubic yards?
Enter the area in square feet and the depth of material, then calculate: cubic feet = area x depth (ft), and cubic yards = cubic feet / 27. For example, 100 sq ft at 4 inches deep = 100 x (4/12) = 33.3333 ft³ = 1.2346 yd³.
Why do I need the depth to convert square feet to cubic yards?
Because square feet measure area (length x width) and cubic yards measure volume (length x width x depth). Area alone has no single volume answer: 100 square feet at 1 inch deep is 0.3086 yd³, but at 6 inches deep it is 1.8519 yd³. Any calculator that skips the depth question is guessing.
What is the formula for square feet to cubic yards?
The formula is: cubic yards = area (sq ft) x depth (ft) / 27. If your depth is in inches, divide by 12 first. One cubic yard always equals 27 cubic feet, so the last step is always dividing by 27.
How many cubic yards is 100 square feet at 4 inches deep?
1.2346 cubic yards (1.2345679 yd³ exact). The math: 100 x (4/12) = 33.3333 cubic feet, then 33.3333 / 27 = 1.2346 cubic yards. Add 10% waste and you get 1.3580 yd³.
How many bags of mulch do I need for 100 square feet?
For 100 sq ft at 3 inches deep you need 25 cubic feet of mulch. In 2 ft³ bags that is 25 / 2 = 12.5, so buy 13 bags (14 with 10% waste, since 13.75 rounds up). The calculator above rounds bag counts up automatically and applies your waste percentage first.
How many 2 cubic foot bags are in a cubic yard?
One cubic yard = 27 cubic feet, so it holds 13.5 bags of 2 ft³; you must buy 14 bags. A 3 ft³ bag gives exactly 9 bags per cubic yard (27 / 3 = 9).
How many cubic yards fit in a concrete truck?
A full ready-mix truck carries about 8 to 10 cubic yards. For small jobs, many suppliers charge a short-load fee on orders under about 2 cubic yards, so a 200 sq ft patio at 6 inches (3.7037 yd³) is usually truck-ordered, while anything under ~1 yd³ is often cheaper in bags. Confirm minimums with your local supplier.
How much area does one cubic yard cover at 4 inches deep?
81 square feet. Coverage = 27 cubic feet / depth in feet, so 27 / (4/12) = 81 sq ft. At 3 inches deep one cubic yard covers 108 sq ft; at 6 inches it covers 54 sq ft.
How do I convert cubic yards back to depth over an area?
Use depth (inches) = cubic yards x 27 / area (sq ft) x 12. For example, 2 cubic yards spread over 100 sq ft gives 2 x 27 / 100 x 12 = 6.48 inches deep. The reverse mode above does this calculation for you.
What is the difference between square feet to cubic feet and to cubic yards?
Cubic feet are the intermediate step: 100 sq ft x 4 in = 33.3333 ft³. Cubic yards just divide that by 27: 33.3333 / 27 = 1.2346 yd³. Use cubic feet for small jobs and bag math; use cubic yards for bulk mulch, soil, gravel, and concrete-truck orders.
How much extra material should I order for waste?
Order 10% extra as the standard: 1.2346 yd³ becomes 1.3580 yd³. Use 5% for flat, simple areas, and 15-20% for mulch that settles or irregular shapes. For concrete, 5-10% covers spillage and form over-excavation.
How do I convert square meters to cubic yards?
Convert to square feet first: 1 square meter = 10.7639 square feet. So 10 m² = 107.639 sq ft; at 4 inches deep that is 107.639 x (4/12) / 27 = 1.3289 yd³. Then follow the same formula.
Can I use this calculator for soil, gravel, or topsoil?
Yes. The volume math is identical for any bulk material: area x depth / 27. For topsoil, compact the depth slightly less than the target (soil settles ~20-30% when tamped); for gravel, a 10-15% waste allowance covers compaction and uneven subgrade.
How many square feet is one cubic yard at 3 inches deep?
108 square feet. At 3 inches (0.25 ft), one cubic yard (27 ft³) covers 27 / 0.25 = 108 sq ft. This is the standard reference depth for mulch coverage charts.
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