Foundation Area
120 sq ft
Gravel
1.48 yd3
Concrete
0.00 yd3
Shed Footprint
120
square feet
Gravel
1.48 yd3
Concrete
0.00 yd3
Skids
3
Blocks
16
Inputs
Result
This is a common starting point for a compact backyard shed foundation.
Inputs
Result
12 x 16 = 192 sq ft. At 4 inches thick, concrete volume is 192 x (4/12) / 27 = 2.37 yd3. A 4-inch gravel sub-base adds another 2.4 yd3.
That depends on shed size, climate, drainage, and permanence. Gravel pads are common for many backyard sheds, while concrete slabs are better for heavier sheds or finished interiors.
Many shed foundations still need both a compacted gravel base and, in some builds, a poured slab or block support system. Separating them makes material planning more accurate.
A 4-inch compacted gravel base is the standard for most backyard sheds. Larger sheds or sites with poor drainage may benefit from 6 inches. The gravel promotes drainage and prevents the shed floor from sitting in pooled water.
| Gravel Depth | Best For | Yards for 10x12 Pad |
|---|---|---|
| 4 in | Standard backyard shed | ~1.5 yd³ |
| 6 in | Poor drainage or large shed | ~2.2 yd³ |
| 8 in | Heavy equipment shed | ~3.0 yd³ |
Concrete slabs are best for permanent sheds, heavy equipment storage, and workshops. Concrete deck blocks or skids work well for lighter utility sheds and are much easier to install without mixing concrete.
Explore deck, pergola, fence, and concrete calculators for outdoor builds.
Last Updated: Mar 11, 2026
This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.