How Much Gravel for a Shed Base?

The short answer

Make the pad 12 inches larger than the shed on every side (the shed footprint plus 2 feet each way), and plan on 4–6 inches of compacted #57 stone. The formula is the usual one: (length × width × depth in feet) / 27. A 10×12 shed gets a 12×14 pad; at 6 inches that's (12 × 14 × 0.5) / 27 = 3.11 cubic yards, about 4.36 tons. Round up and order — suppliers sell whole and half yards, and compaction eats roughly 10–20% of loose volume.

Pad-size chart: shed footprint → yards and tons

Pad footprint = shed dimensions plus 12 inches on each side. Tons = yards × 1.4 (gravel runs about 2,800 lbs per cubic yard). Add 10–20% over the chart numbers for compaction loss and grade irregularities.

Sanity check on the 10×12 row at 6 inches: 12 × 14 × 6 / 324 = 3.11 yards, and 3.11 × 1.4 = 4.36 tons. (Note: the numbers above use the formula pad L × pad W × depth(in) / 324 — check your calculator result against any row before ordering.)

Depth rules: 4, 6, or 8 inches?

Depth here means compacted depth. Use 4 inches on firm, well-drained soil in mild climates. Use 6 inches as the default for most sheds — it handles drainage, frost, and a mower-grade of imperfection in the subgrade. Go 6–8 inches in freeze-thaw regions or over soft, expansive clay: deeper stone puts the pad above more of the freeze line's heave and spreads the shed's load across mushy soil. Whatever target you pick, install loose stone about 20–25% deeper than the finished depth, then compact down to it.

The right stone: why #57

#57 stone is angular crushed rock, roughly 1/2 to 1 inch across. The angular faces lock together under compaction, and the open gaps between pieces drain water straight through instead of pooling under the shed — the two things a shed pad has to do. Compare with the alternatives: pea gravel is round and never compacts — it shifts under skids and walks out from under the pad (see our crushed stone vs pea gravel guide for the full breakdown). Crusher run / dense grade packs harder because of its fines, but it holds water — fine for a driveway, less ideal where a wooden shed floor sits inches above. #57 is also the stone to ask for by name at the quarry: it's a standard gradation, so you won't get a surprise load of something else.

Build steps: fabric, edging, lifts

1. Mark and strip. Lay out the pad footprint and remove sod and topsoil down about 6 inches so the stone sits on stable subgrade, not spongy organics. 2. Landscape fabric. Roll non-woven geotextile fabric over the excavation — it separates stone from soil so the pad can't sink, and stops weeds. Overlap seams 6 inches. 3. Timber edging. Set a square frame of pressure-treated 4×4 or 6×6 timbers, level all around, pinned with rebar stakes. The frame is your form: it holds the stone in, gives you a screed reference, and keeps lawn equipment from shoving gravel onto the grass. 4. Place stone in lifts. Dump 2–3 inch layers, rake level, lightly wet each lift, and run a plate compactor over it before the next layer goes down. 5. Final grade. The finished pad should sit roughly level — a quarter-inch of fall per foot away from the shed keeps water moving off. Set the shed skids or blocks and re-check level before the walls go up.

Freeze-thaw note

In cold climates, water trapped under a pad freezes, expands, and heaves one corner of the shed — the classic spring “why is my shed leaning” discovery. The defenses stack: go 6–8 inches deep, keep the fabric layer (it stops capillary water from wicking up into the stone), and make sure the subgrade slopes so water leaves rather than sitting under the pad. If your site holds water after rain, extend the pad's gravel a foot past the edging as a drainage apron, or add a gravel base layer the same way a paver patio uses one — different project, same layer logic.

Delivery and cost reality

At 1.4 tons per yard, most shed pads need a dump-truck delivery — the 4.36-ton load for a 10×12 shed at 6 inches is about what a single-axle dump carries, and the 7.99-ton load for a 12×20 pushes into two trips or one tri-axle. Bulk #57 typically runs $35–60 per ton plus a $50–150 delivery fee, so a standard 6-inch pad lands in the $150–400 range all-in. Suppliers often have a minimum (1–3 yards); if your pad is small, splitting a load with a neighbor is the classic move. And confirm access: the truck needs to dump within wheelbarrow distance of the pad, or the savings evaporate into labor.

Common mistakes

Pad exactly the shed size. Water drips off the roof edge and lands on bare soil, eroding the perimeter; the extra 12 inches all around is a drip zone and working margin. Stone over grass, no fabric. The pad sinks into the lawn within a season. No edging. Gravel migrates — mowers fling it and foot traffic walks it outward. One dump, one pass. A full 6 inches compacted in a single lift bridges and leaves soft spots underneath. Pea gravel. Looks tidy on day one, shifts forever after. Pad below grade. If the finished pad sits lower than the surrounding lawn, it becomes a pond — build it a couple of inches proud.