Gravel Shed Pad: Size, Stone Quantity and Cost Planner

A gravel pad for a shed starts with its maker’s requirements

A level pad does not automatically make every shed foundation acceptable. Floor construction, skids, anchors, bearing capacity, access and local approvals matter. Obtain the exact model’s site-preparation instructions before buying stone or selecting depth.

For an identifiable example, Horizon Structures recommends a level pad of ¾-inch crushed stone, 3–4 inches deep, and dimensions 1 ft larger overall than its shed: a 10 × 14 ft building on at least an 11 × 15 ft pad. That means 6 inches per side for a centered building, not 1 ft per side. Its guidance also discusses local pier requirements and discourages cinder-block support. These are that maker’s instructions, not a rule for every shed. Horizon Structures site-preparation guidance (external source).

The planner therefore takes an editable extension on each side and a specified depth. It does not select a universal 6-inch pad, timber section, stake spacing, floor-joist size or frost footing.

Clean crushed stone or crusher run?

Clean aggregate and dense-graded material have different roles. Follow the shed maker’s accepted material and foundation assembly. Neither “crusher run is always right” nor “crusher run always traps water” establishes suitability for all sheds.

Use the stone-selection guide to compare product descriptions. The crusher run calculator can plan an order when a dense-graded product is actually specified; it is not a shed-foundation approval. Fabric, drainage and anchors also need the selected installation detail.

Do not treat driveway underlay guidance as a shed specification. The driveway fabric guide explains separation questions for driveways; transfer only principles that your shed designer confirms. If water collects at the proposed pad, evaluate drainage before ordering; the French drain planner helps budget a separately specified drain.

10 × 12 ft shed, 12 × 14 ft example pad

This illustration selects a 1 ft apron on each side and 6 in uniform depth. These inputs differ from Horizon’s example and are not attributed to it. Pad area is 168 sq ft and perimeter is 52 ft. Geometric volume is 168 × 6 ÷ 324 = 3.1111 yd³. With an illustrative factor of 1 and 10% independent handling, the order is 3.4222 yd³. At an assumed matching density of 1.4 US ton/yd³ it is 4.7911 US short tons.

Try example loads this itemized scenario. At 8 inches instead of 6, stone order rises to 4.5630 yd³ and stone cost to $296.59; the known subtotal becomes $636.79. Removing edging from the 6-inch scenario removes $208 and gives $354.64. Each change affects the actual corresponding line.

Stone quantities by pad size and depth

Going from 4 to 6 inches increases that uniform layer by 50%. Going from 6 to 8 increases it by one third. Allowance and supplier rounding are additional steps, not part of these geometric figures.

On slopes, a single average depth is valid only for a defined uniform footprint with a known linear depth change. It does not size a retaining wall or make unsupported fill safe. Ask for grading, retention and drainage details before using the calculator.

Budget site work, access and installation separately

A Southern Nursery in Greenville, SC lists #57 gravel and crusher run at $40/ton, before separately described delivery. Confirm units, tax, minimums and suitability. Supplier listing (external source).

The local supplier listing does not establish a delivered shed-pad price or approve the product for your shed. Use your exact product quote and unit. The planner prices stone by volume; convert a per-ton quote only with a matching confirmed density, or request the volume rate.

• Confirm setback, zoning, building, anchoring and foundation requirements with the responsible local authority. A size threshold from another jurisdiction is not approval.
• Confirm delivery-machine access, overhead clearance and the pad location with the shed mover.
• Price excavation, unsuitable-soil removal, disposal and any engineered retaining work.
• Record the stone state, compaction detail, edging and required separation material.
• Confirm level tolerance and acceptance checks with the maker before shed delivery.

For planted beds around the shed, calculate their separate purchase with the mulch calculator. Keep that landscape order separate from foundation stone.

An installed square-foot quote may change when depth or edging changes. The planner shows area-based arithmetic but does not invent a revised contractor rate. For material changes, use itemized mode or obtain a replacement written quote.

If the selected model requires a slab, use the concrete volume calculator and concrete quote planner. Those tools estimate quantities and costs; they do not approve the shed foundation. Use the delivery guide for bulk truck access.

Frequently asked questions