How Much Crushed Stone for 400 Square Feet?
How much crushed stone for 400 square feet depends on depth. At 4 inches you need about 4.94 cubic yards, roughly 6.9 tons at 1.4 tons per yard. Going to 6 inches raises it to 10.4 tons.
Volume and tonnage calculator →Crushed stone for 400 sq ft by depth
| Depth | Cubic yards | Tons | Tons +10% |
|---|---|---|---|
| 2 in | 2.47 | 3.5 | 3.8 |
| 3 in | 3.70 | 5.2 | 5.7 |
| 4 in | 4.94 | 6.9 | 7.6 |
| 6 in | 7.41 | 10.4 | 11.4 |
Working it out
- 400 sq ft × (4 ÷ 12) ft = 133.3 cubic feet.
- ÷ 27 = 4.94 cubic yards.
- × 1.4 tons per yard = 6.9 tons.
About crushed stone
Crushed stone has fractured faces, so the pieces interlock when compacted. That is why it holds a driveway or pad shape better than round stone of the same size. Typical weight: 1.35 to 1.5 tons per cubic yard.
Ordering checklist
- Measure odd shapes in pieces. Split curves and L-shapes into rectangles and add them.
- Add a margin. About 10 percent covers compaction and low spots.
- Bulk or bags. Bulk delivery is the practical choice here.
- Prep first. Remove sod, compact the subgrade and set edging before the stone arrives.
Use the volume and tonnage calculator for any other size.
When to choose crushed stone
Good uses:
- Driveway top courses and parking pads
- Shed and hot tub bases
- Backfill behind walls when a clean size is used
Poor fit for:
- Barefoot areas, since angular stone is rough
- Play areas
- Places that need a smooth rolling surface for wheels
Quick reference numbers
- Per inch over 100 sq ft: about 0.43 tons of crushed stone (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.3 tons.
- Another size for comparison: a 15x30 area at 4 inches takes about 7.8 tons.
- Weight used here: about 1.4 tons per cubic yard.
Mistakes that throw off the order
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
- Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
Questions people ask
How many tons of crushed stone for 400 square feet?
About 6.9 tons at 4 inches deep.
How many cubic yards of crushed stone for 400 square feet?
About 4.94 yards at 4 inches.
How much crushed stone for 400 square feet at 2 inches?
About 3.5 tons, or 2.47 cubic yards.
How much does a yard of crushed stone weigh?
About 1.35 to 1.5 tons.
Should I add extra?
Yes, about 10 percent is a common allowance.
Related guides
- How Much Does a Ton of Crushed Stone Cover?
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Much Does a Ton of Gravel Cover? Depth Chart
- How Much Crushed Stone for 250 Square Feet?
- How Much Crushed Stone for 300 Square Feet?
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