How to use the square feet to cubic yards calculator
- 1
Measure the area
Find the area in square feet. For a rectangle, multiply length in feet by width in feet. For odd shapes, split the area into rectangles and add them.
- 2
Choose the depth
Enter how deep the material will sit and pick the depth unit. Most landscaping and base layers are entered in inches.
- 3
Add quantity or waste if needed
Use the optional quantity field for several identical areas, and add a waste percentage for spillage, compaction, or trimming.
- 4
Read the result
The calculator shows cubic yards along with cubic feet and cubic meters. Round up when you are ready to order.
Formula
Cubic yards = square feet x depth (in) / 324
The number 324 comes from 27 cubic feet in a cubic yard multiplied by 12 inches in a foot. When the depth is in feet instead, the formula is square feet times depth in feet divided by 27.
Two ways to write the same formula
Pick the version that matches the unit your depth is in. Both give the same result.
- Depth in inches
- Cubic yards = square feet x depth (in) / 324
- Best when your thickness is in inches, which is common for landscaping layers.
- Depth in feet
- Cubic yards = square feet x depth (ft) / 27
- Convert inches to feet by dividing by 12, then divide by 27.
Worked example
A 600 square foot patio base is filled 4 inches deep.
- 1Start with the area: 600 square feet.
- 2Multiply by the depth in inches: 600 x 4 = 2,400.
- 3Divide by 324: 2,400 / 324 = 7.41 cubic yards.
A 600 square foot area at 4 inches deep needs about 7.41 cubic yards.
Why a depth is required
Area describes a surface in two dimensions. Volume describes the space a material fills in three dimensions. A pile of gravel 1 inch deep and the same pile 6 inches deep cover the same square footage but use very different amounts of material, so the depth is what turns an area into a volume.
That is why this tool always asks for a thickness. Once you supply it, the math is exact. To go the other direction and find how much area a known volume covers, use the cubic yards to square feet calculator.
Where the number 324 comes from
One cubic yard is 27 cubic feet. One foot is 12 inches. Multiplying 27 by 12 gives 324, which is the number of square feet that one cubic yard covers at a depth of exactly 1 inch.
Because the factor is exact, dividing your area times depth in inches by 324 converts cleanly to cubic yards for any project size.
Common uses
Converting square feet to cubic yards comes up whenever you know an area and a layer thickness, such as:
- Topsoil or compost spread across a lawn or garden bed
- Mulch laid over a planting area
- Gravel or crushed stone for a driveway or path base
- Sand bedding under pavers
- A concrete slab of a set thickness
Common mistakes
A few simple errors cause most bad estimates:
- Leaving depth out and treating square feet as if they were already a volume
- Mixing units, such as entering area in square feet but depth in a different system without converting
- Forgetting to convert depth from inches to feet when using the divide by 27 version
- Rounding the area or depth too early instead of at the final step
- Ignoring an irregular area that should be split into rectangles first
Square Feet to Cubic Yards by Depth
Cubic yards needed for each area and depth. Find your area on the left and your depth across the top. Every value is square feet times depth in inches divided by 324.
| Area | 1 in | 2 in | 3 in | 4 in | 6 in | 8 in | 12 in |
|---|---|---|---|---|---|---|---|
| 50 sq ft | 0.154 | 0.309 | 0.463 | 0.617 | 0.926 | 1.23 | 1.85 |
| 100 sq ft | 0.309 | 0.617 | 0.926 | 1.23 | 1.85 | 2.47 | 3.7 |
| 150 sq ft | 0.463 | 0.926 | 1.39 | 1.85 | 2.78 | 3.7 | 5.56 |
| 200 sq ft | 0.617 | 1.23 | 1.85 | 2.47 | 3.7 | 4.94 | 7.41 |
| 300 sq ft | 0.926 | 1.85 | 2.78 | 3.7 | 5.56 | 7.41 | 11.11 |
| 500 sq ft | 1.54 | 3.09 | 4.63 | 6.17 | 9.26 | 12.35 | 18.52 |
| 750 sq ft | 2.31 | 4.63 | 6.94 | 9.26 | 13.89 | 18.52 | 27.78 |
| 1,000 sq ft | 3.09 | 6.17 | 9.26 | 12.35 | 18.52 | 24.69 | 37.04 |
| 1,500 sq ft | 4.63 | 9.26 | 13.89 | 18.52 | 27.78 | 37.04 | 55.56 |
| 2,000 sq ft | 6.17 | 12.35 | 18.52 | 24.69 | 37.04 | 49.38 | 74.07 |
Frequently asked questions
- Can you convert square feet to cubic yards without a depth?
- No. Square feet measure area and cubic yards measure volume. You must include the depth or thickness of the material before the conversion is possible.
- What is the formula for square feet to cubic yards?
- Cubic yards equals square feet times the depth in inches divided by 324. If the depth is in feet, multiply square feet by depth in feet and divide by 27 instead.
- Why do you divide by 324?
- There are 27 cubic feet in a cubic yard and 12 inches in a foot. Multiplying 27 by 12 gives 324, the square feet that one cubic yard covers at 1 inch deep.
- How many cubic yards is 1,000 square feet?
- It depends on the depth. At 2 inches, 1,000 square feet is about 6.17 cubic yards. At 4 inches it is about 12.35 cubic yards. Use the table above to read other depths.
- How do I handle an irregular area?
- Split the area into rectangles, find the square footage of each, and add them together before entering the total. The cubic yard calculator can also combine several sections for you.
- Does this work for concrete?
- Yes. The volume in cubic yards is the same for any material at a given area and thickness. Only the weight and the way you order it change by material.
- Should I round up the result?
- For ordering, rounding up is usually safer so you do not run short. Keep the exact decimal while planning and round at the ordering stage.
- What depth should I use?
- Use the finished thickness your project calls for. Confirm the recommended depth for your specific material and application with your supplier or project specification.
Results use the exact factors of 27 cubic feet per cubic yard and 12 inches per foot. Table values are generated by the shared calculation engine, never hand-typed. See the YardCalc calculation methodology for how conversions are verified.
Results are planning estimates. Last reviewed 2026-06-16.