How Much Crushed Stone for an 18x20 Carport?
How much crushed stone for an 18x20 carport: about 6.2 tons at 4 inches deep and 9.3 tons at 6 inches, over 360 square feet.
Volume and tonnage calculator →The math
- Area: 360.0 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic yards: 360.0 × 0.333 ÷ 27 = 4.44 yd³.
- Tons: × about 1.4 tons per yard = 6.2 tons.
The crushed stone calculator does this for any size.
Related: How Much Crusher Run for an 18x20 Carport?
Crushed stone needed by depth
| Depth | Cubic yards | Tons of crushed stone | Tons +10% |
|---|---|---|---|
| 4 in | 4.44 | 6.2 | 6.8 |
| 6 in | 6.67 | 9.3 | 10.3 |
| 8 in | 8.89 | 12.4 | 13.7 |
Carport pad tips
Metal carport kits anchor to concrete, asphalt or ground anchors in soil or gravel. Check your kit’s anchor type before building the pad, and extend the stone a foot past the frame so posts sit on compacted base.
Related: How Much Crushed Stone for a 18x20 Parking Pad?
Depth for vehicles
Four inches works on firm ground for cars. Six inches is safer for trucks, heavy SUVs or soft soil.
Buying the stone
If you haul it yourself, a typical half-ton pickup should carry only about half a cubic yard of stone, well under what the bed looks like it can hold. Crushed stone has angular faces that lock together under a compactor, which is why it holds a pad shape. Round up by about 10 percent for compaction and uneven ground.
Tools for the job
A flat shovel, a steel rake, a wheelbarrow and a rented plate compactor cover most residential pads. A landscape rake or the back of a rake levels the top layer, and a long straightedge or a level string shows high and low spots before the final pass.
Planning the cost
Quarries and landscape suppliers set their own prices, and they change by region and season. Get the price per ton, the delivery fee and the minimum order. If two products will both work, compare cost per square foot at your depth rather than cost per ton.
Questions people ask
How many tons of crushed stone for an 18x20 carport?
About 6.2 tons at 4 inches or 9.3 at 6 inches.
Can a carport sit on gravel?
Many metal carports anchor into compacted gravel with ground anchors; check your kit.
How many tons of crushed stone are in a cubic yard?
Roughly 1.4 tons for planning, but suppliers vary with stone size and moisture.
Do I need to compact it?
Yes for anything that carries weight. Compact in lifts of a few inches with a plate compactor.
Related guides
- How Much Does a Ton of Gravel Cover? Depth Chart
- Tons to Cubic Yards for Gravel: Conversion Chart
- Crushed Stone vs Gravel: Differences and Best Uses
- Geotextile Fabric for Driveways: Woven vs Nonwoven and How Much You Need
- Compacting a Driveway Gravel Base in Lifts
- How Much Crusher Run for a 12x24 Carport?
- How Much Gravel for an 18x20 Carport?
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