Gravel Shed Base Calculator
A gravel shed base calculator finds crusher run at 1.5 tons per yd³: a 12 × 10 ft pad 4 in deep takes 2.22 tons, or 2.44 with 10% extra, $98 at $40 a ton.
What your order looks like
One bulk delivery is usually easier than hauling it yourself.
1.48 yd³ · 2.2 tons
20 wheelbarrow trips (2 cu ft each)
3 pickup loads (0.75 ton each)
1 small dump truck load (6 tons each)
Rules of thumb: A wheelbarrow trip is 2 cubic feet of heavy material, about 200 lb, a load most people can push. A pickup load is 0.75 ton, the payload of a full-size half-ton pickup (1,500 lb). A small single-axle dump truck carries about 6 tons.
Gravel shed base calculator: the short answer
A gravel shed base calculator takes the pad’s length, width and depth, converts the volume to cubic yards, and multiplies by crusher run’s 1.5 tons per cubic yard. A 12 × 10 ft pad at 4 inches deep comes to 2.22 tons, or 2.44 tons if you add 10% for compaction and a rough edge.
Crusher run is the default here because it packs hard and holds a shed’s weight evenly.
The formula in plain words
Cubic yards = length × width × (depth in inches ÷ 12) ÷ 27. Tons = cubic yards × 1.5. Cost = tons × your price per ton. The 10% box multiplies the tons by 1.1 before the cost is worked out.
Worked example, a 10 × 8 shed
Shed footprint 10 × 8 ft, plus 1 ft on each side, gives a 12 × 10 ft pad. Depth 4 inches, price $40 a ton.
- Cubic feet: 12 × 10 × (4 ÷ 12) = 40
- Cubic yards: 40 ÷ 27 = 1.4815
- Tons: 1.4815 × 1.5 = 2.22
- With 10% extra: 2.22 × 1.1 = 2.44 tons
- Cost: 2.22 × $40 = $88.89, or $97.78 with the extra
Worked example, a larger shed on soft ground
A 14 × 10 ft shed gets a 16 × 12 ft pad. The soil is clay, so you build it 6 inches thick.
- Cubic yards: 16 × 12 × 0.5 ÷ 27 = 3.5556
- Tons: 3.5556 × 1.5 = 5.33
- With 10% extra: 5.87 tons
- Cost at $40 a ton: $234.67
The same 16 × 12 ft pad at 4 inches would take 3.56 tons, so the extra 2 inches adds 1.78 tons to the order.
Tons by pad size and depth
| Pad size | 4 in | 6 in |
|---|---|---|
| 8 × 6 ft | 0.89 | 1.33 |
| 10 × 8 ft | 1.48 | 2.22 |
| 12 × 10 ft | 2.22 | 3.33 |
| 16 × 12 ft | 3.56 | 5.33 |
| 20 × 16 ft | 5.93 | 8.89 |
Values are tons before the 10% extra.
How to measure
- Measure the shed’s outside footprint, including any overhanging eaves that sit on the foundation.
- Add about 1 ft to each dimension.
- Enter the finished, compacted depth. The waste box covers the loose-to-compacted difference.
- On a sloped site, dig the high side down to level rather than building up the low side with extra stone, since the extra stone can cost more than the digging.
Common mistakes
- Making the pad the exact size of the shed. The edges then sit on loose stone.
- Skipping the compactor. A raked, uncompacted pad can drop an inch under the first load.
- Entering depth in feet. The depth box takes inches.
- Ordering by yards when the quarry sells by the ton. A yard of crusher run weighs about 1.5 tons, so mixing the two units throws the order off by half.
Before you order
Read the shed maker’s foundation sheet first. Some kits specify a pad size, a depth, or a requirement for treated timbers on top of the stone. If you plan to set the shed on skids or a wood frame, the frame spreads the weight, and a 4 inch pad is usually fine for a small shed on firm ground.
Lay landscape fabric under the stone if the soil is soft, so the crusher run doesn’t mix into the dirt over time. Fabric adds nothing to the tonnage, but it keeps the depth you paid for.
Finally, check delivery. A truck dumps the whole load in one pile, usually in the driveway, and you move it by wheelbarrow. A 2.44 ton order is about 1.6 cubic yards, or around 7 wheelbarrow loads at 6 cubic feet each.
Related pages
For a similar pad under a car, see the gravel parking pad calculator. The crusher run calculator covers other uses of the same stone, and the gravel base calculator sizes bases under pavers and patios.
Frequently asked questions
How big should the gravel pad be compared to the shed?
Make it about 1 foot bigger than the shed on every side. For a 10 × 8 ft shed that means a 12 × 10 ft pad. The margin keeps the shed's edge from sitting on a crumbling shoulder and gives rain a place to drain away from the walls.
Why use crusher run instead of washed gravel?
Crusher run is angular stone mixed with fine dust. When you compact it, the pieces lock together into a firm surface. Washed round stone stays loose and can let a shed settle on one corner.
How deep should a shed base be?
Four inches of compacted stone is a common minimum for a small shed on firm ground. Soft or clay soil, a larger building or heavy contents call for 6 inches, often over landscape fabric. Check the shed maker's foundation instructions, which sometimes specify more.
Do I have to level the ground first?
Yes. Strip the sod, dig to a consistent depth and check it with a level or string line. Gravel placed over a lumpy surface comes out at uneven thickness, and thin spots settle first.
Should I compact the stone?
Yes. Spread it in layers no thicker than about 4 inches and run a plate compactor over each. Compacting is why the waste box matters, since loose stone loses height when it is packed down.
Should I tick the 10% waste box?
For a shed base, yes. Compaction and a slightly rough excavation both eat stone. On the 12 × 10 ft example it moves the order from 2.22 to 2.44 tons.
Estimates only. Verify quantities with your supplier before purchasing.