Square Feet to Cubic Yards
Enter a surface area and depth to calculate the volume of material you need.
Free to use. Calculations run in your browser.
At a glance
Square Feet to Cubic Yards
Cubic yards = square feet × depth in inches ÷ 324. If depth is in feet, use square feet × depth in feet ÷ 27. Area alone does not determine volume.
Area and depth
Why the conversion needs depth
Square feet measure a surface. Cubic yards measure a three dimensional space. The same 400 square feet can hold different quantities depending on whether the material is 1 inch, 4 inches, or 12 inches deep. If you have length and width instead of an area figure, calculate the surface area first.
yd³ = ft² × depth (in) ÷ 324
yd³ = ft² × depth (ft) ÷ 27
The 324 comes from 12 inches per foot multiplied by 27 cubic feet per cubic yard. The calculator converts the depth to feet before multiplying, so mixed and metric units follow the same dimensional method.
Area and depth
Examples for 400, 600, and 800 square feet
| Area | At 3 inches | At 4 inches | At 6 inches |
|---|---|---|---|
| 100 ft² | 0.925926 yd³ | 1.234568 yd³ | 1.851852 yd³ |
| 400 ft² | 3.703704 yd³ | 4.938272 yd³ | 7.407407 yd³ |
| 600 ft² | 5.555556 yd³ | 7.407407 yd³ | 11.111111 yd³ |
| 800 ft² | 7.407407 yd³ | 9.876543 yd³ | 14.814815 yd³ |
| 1000 ft² | 9.259259 yd³ | 12.345679 yd³ | 18.518519 yd³ |
For example, 400 ft² at 4 inches is 400 × 4 ÷ 324 = about 4.938 yd³. These are measured volumes before allowance or order rounding. Each table column states its depth; there is no depth free square foot conversion.
Area and depth
Concrete, soil, mulch, and acres
Use the specified slab thickness for concrete, the new layer thickness for mulch, and the space being filled for soil. Geometry is shared, while material selection, compaction, yield, and ordering allowances remain separate decisions.
The area unit selector also accepts acres. One acre is 43,560 square feet, so one acre covered 1 inch deep is about 134.444 cubic yards. A different depth changes that result proportionally.
If you need bags, quoted cost, several depths, or multiple shapes, use the appropriate material calculator. To work from a known cubic yard quantity back to coverage, use the reverse coverage tool.
Common questions
Square Feet to Cubic Yards questions, answered.
Can square feet be directly converted to cubic yards?
A depth must be supplied. A square foot has two dimensions and a cubic yard has three. A conversion that omits depth is missing part of the required information.
How many cubic yards are in 1,000 square feet?
At 4 inches deep, 1,000 square feet is about 12.346 cubic yards. At 3 inches it is about 9.259 cubic yards. Enter your actual depth instead of assuming either example.
Do I use slab thickness or the height of the forms?
Use the thickness of concrete that will actually occupy the space. For thickened edges or separate sections, calculate the additional volume separately without double counting the ordinary slab.
Can I start with square meters or square yards?
Yes. Change the known area unit and choose a depth unit. The outputs include cubic feet and cubic meters as well as cubic yards.
Check the basis