Shed Base Gravel Calculator
Crushed stone needed for a level shed base. Yards, tons and bags for common shed footprints at a 4-inch depth.
A shed sits best on 4 inches of compacted crushed stone, extending about a foot past the building on each side. Rows assume an 8 ft wide pad.
Crushed stone at 4 in deep · density ≈ 1.35 tons/yd³ · 0.5 ft³ bags.
| Length × 8 ft | Cubic yards | Tons (est.) | 0.5 ft³ bags |
|---|---|---|---|
| 8 ft | 0.79 | 1.07 | 43 |
| 10 ft | 0.99 | 1.33 | 54 |
| 12 ft | 1.19 | 1.60 | 64 |
| 16 ft | 1.58 | 2.13 | 86 |
| 20 ft | 1.98 | 2.67 | 107 |
Tonnage is an estimate from loose, dry bulk density; damp or compacted material weighs more. Order ~5–10% extra for settling.
Crushed stone (also sold as "processed gravel" or "road base") makes an excellent shed foundation because it compacts firmly, drains water away from the structure, and prevents the shed floor from sitting in contact with damp ground. It is also far easier to install than a concrete slab and adjustable if the shed is ever moved.
Extend the gravel pad 6–12 inches beyond the shed footprint on each side. This keeps the skids or blocks off bare soil and gives you a clean surface to walk on around the shed. Compact the gravel in 2-inch lifts with a plate compactor or tamper for a stable, level base.
Frequently asked questions
How deep should a gravel base be for a shed?
Four inches of compacted crushed stone is the standard minimum for a small residential shed (under 12 × 12 ft). Larger or heavier sheds benefit from 6 inches. The stone should be compacted in layers with a plate compactor.
What type of stone is best for a shed base?
Crushed stone (angular, processed gravel) is best because the sharp edges compact into a stable, interlocked layer. Pea gravel or river rock are decorative but shift underfoot and provide an unstable base. "Crusher run" (a mix of crushed stone and stone dust) compacts even more firmly.
Should I put landscape fabric under shed gravel?
Yes — landscape fabric prevents weeds from growing through the gravel and keeps the stone from gradually working into the soil. Use a heavy-duty woven fabric, not a thin plastic sheet, and extend it 6 inches past the gravel perimeter.