Leveling a lawn or preparing ground for new grass is the same calculation as any other topsoil job. What is different is the scale: a very small depth over a large area.
Volume (cu ft) = area (sq ft) × depth (in) ÷ 12
Cubic yards = cu ft ÷ 27
Each 1/4 inch over 1,000 sq ft ≈ 20.8 cu ft ≈ 0.77 cu yd
1,000 sq ft at three depths
A quarter inch looks like nothing on a tape measure and still comes to nearly a cubic yard. The depths below are examples. They are not advice about how much to put on a lawn.
| Depth (example) | Volume | Bulk to buy |
|---|---|---|
| 1/4 in | 20.8 cu ft · 0.77 yd³ | 0.77 yd³ |
| 1/2 in | 41.7 cu ft · 1.54 yd³ | 1.54 yd³ |
| 1 in | 83.3 cu ft · 3.09 yd³ | 3.09 yd³ |
This example assumes
- A 1,000 sq ft area entered as a known area
- No extra allowance, the planner’s starting value
- Bulk delivery; the planner also shows bag counts
Choosing a depth
Depth is the number that decides the order, and it depends on your lawn, your soil and what you are trying to fix. Published rules of thumb vary, so treat any single figure with caution. Your state’s university extension office is a better place to ask, and it knows your grass and your soil.
Filling deeper low spots
A deep depression is a different job from a thin top layer. Measure its area and average depth separately and add the volumes, rather than applying one depth to the whole lawn. The planner handles each as its own entry if you run it twice and add the results.
What changes the estimate?
- The depth you choose, which is the main driver
- Total area, including areas that get a different depth
- Settling or uneven ground, which the allowance can cover
- Whether you are buying by the yard or in bags, since large areas favor bulk
New grass from seed or sod
If you are laying sod, the sod guide covers the sod itself. The topsoil beneath it is this calculation with the depth you decide for your site.