How Much Gravel for a 20x20 Carport?
How much gravel for a 20x20 carport: about 6.9 tons at 4 inches deep and 10.4 tons at 6 inches, over 400 square feet.
Volume and tonnage calculator →The math
- Area: 400.0 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic yards: 400.0 × 0.333 ÷ 27 = 4.94 yd³.
- Tons: × about 1.4 tons per yard = 6.9 tons.
The gravel calculator does this for any size.
Related: How Much Crushed Stone for a 20x20 Carport?
Gravel needed by depth
| Depth | Cubic yards | Tons of gravel | Tons +10% |
|---|---|---|---|
| 4 in | 4.94 | 6.9 | 7.6 |
| 6 in | 7.41 | 10.4 | 11.4 |
| 8 in | 9.88 | 13.8 | 15.2 |
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 Crusher Run for a 20x20 Carport?
Depth for vehicles
Use 6 inches of compacted stone if you park pickups or trailers under it; 4 inches is the minimum for cars on firm soil.
Getting it delivered
Most quarries and landscape yards deliver by the ton; ask whether there is a minimum and a delivery fee, and where the driver can dump without damaging your lawn. Gravel is a broad label, so confirm whether the yard means crushed or rounded stone and whether it carries fines. The scale ticket is the real weight; tons per yard here is a planning figure.
Measuring the area
Measure length and width in feet at a few points and use the largest figures, since real sites are rarely square. For odd shapes, split the area into rectangles and circles, work out each one and add them together. Depth is the number most people underestimate: drive a stake, run a level string and measure down to the dug-out surface in several spots.
Common mistakes
People often forget that compaction reduces volume, so they come up short. Others order clean, round stone where a packable crushed stone with fines would have stayed put. Finally, dumping the whole load in one pile far from the work area adds hours of wheelbarrow trips.
Questions people ask
How many tons of gravel for a 20x20 carport?
About 6.9 tons at 4 inches or 10.4 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 gravel 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 Crushed Stone for an 18x24 Carport?
- How Much Crusher Run for an 18x24 Carport?
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