How Much Gravel for a 4x8 Shed Base? (2026 Guide)

Gravel for a 4x8 shed base at a glance

A gravel base keeps the shed floor dry and level by lifting it off the soil and letting rain drain away. For a 4x8 ft tool shed the base is a 4-in layer of 3/4-in crushed stone, extended 6 in past the walls on all four sides so the edges of the shed have stone under them too. That border turns the 4x8 ft footprint into a 5 x 9 ft pad = 45 sq ft.

The tonnage column uses a typical 1.5 tons per cubic yard. Real density runs about 1.4-1.6 tons/yd³ depending on the stone's gradation, moisture and how tightly it settles, so confirm the weight with your supplier when you order. A thinner 3-in base is fine on firm, well-drained ground; go to 4 in on soft or clay soil.

Why the base is wider than the shed

The shed frame carries the whole structure on its perimeter, and the walls sit close to the edge of the pad. Extending the gravel 6-12 in beyond the walls gives those edges solid stone underneath, which is what stops them from sinking, shifting or heaving over the first wet season. It also gives rainwater somewhere to drain instead of washing the soil out from under the floor. If you gravel only the bare 4x8 ft = 32 sq ft footprint, you save material - about 0.4 cu yd at 4 in deep - but you lose that edge support.

The math, step by step

For a 4x8 ft shed with a 6-in border and a 4-in-deep bed of 3/4-in crushed stone:

• Base area: shed plus 0.5 ft on each side = 5 x 9 = 45 sq ft.
• Depth in feet: 4 in / 12 = 0.333 ft.
• Volume: 45 x 0.333 = 15 cu ft.
• Cubic yards: 15 / 27 = 0.56 cu yd.
• Order: round 0.56 up to about 0.6 cu yd (0.8-0.9 tons); since most suppliers won't deliver less than a cubic yard, plan on 1 cu yd - the leftover disappears into the border or next project.

Buying bags instead of a bulk delivery? A standard 50-lb bag of crushed stone covers about 0.5 cu ft, so 15 cu ft is roughly 30 bags - carryable in a couple of SUV loads, but bulk is far cheaper at this volume.

Laying the base in four steps

• Excavate about 4-5 in deep across the full 45 sq ft base area (6-in border included) and level the soil, sloping it slightly away from the shed's center.
• Lay weed barrier fabric over the soil so nothing grows up through the gravel and into the floor.
• Add the 3/4-in crushed stone and compact it in two lifts with a hand tamper or plate compactor until the surface is firm, level and about 4 in thick.
• Set the shed on 4x4 timbers laid on the compacted gravel, so the floor framing sits a few inches above the stone and air can move underneath.

Use angular 3/4-in crushed stone, not rounded pea gravel - the crushed pieces lock together and spread the shed's weight, while round stone shifts under load. For a bigger building the same formula scales up, so see how much material a 10x10 shed pad takes for a full breakdown. Building a 10x10 gravel patio instead? That guide covers the crushed-stone base plus a pea gravel surface layer. And if the gravel is for vehicle traffic, how much gravel a driveway needs runs the same area-times-depth math at driveway depth.

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